Thank you, Dr. Srivastava, for choosing this important subject for discussion in this forum. Recently I reviewed the trend of climate change and its impact on soil C and N availability to crop plants. I would like to share with you the salient findings.

(1). There is now unequivocal evidence that the earth’s surface has warmed during the past 100 years, which is mainly attributed to the anthropogenic activity. An analysis of surface air temperatures over India showed that the annual average surface temperatures have increased over the years with a trend of 0.56 °C/100 years, which is close to the global warming trend. These warming trends of surface temperature also may have an impact on carbon and nitrogen stocks of the soils.

(2). The climate model projections based on IPCC AR5 CMIP5 models (Chaturvedi et al. 2012) reveal that surface air temperatures including night time temperatures are expected to increase further. The all-India rainfall and extreme rainfall events are also expected to increase in future. Under the business-as-usual scenario, mean warming over India is likely to be in the range of 1.7-2.0 °C by 2030s and 3.3-4.8 °C by 2080s relative to pre-industrial times. Likewise, all-India precipitation is projected to increase by 4-5% by 2030s and by 6-14% by 2080s compared to the 1961-1990 baseline. There is consistent positive trend in frequency of extreme precipitation days (more than 40 mm d-1) for decades 2060s and beyond. 

(3). Studies on climate change impact on soils of the US Great Plains (Follett et al. 2012) show that soil C and N stocks are strongly negatively related to mean annual temperature and positively related to the ratio of mean annual precipitation to potential evapotranspiration, suggesting that they are equally vulnerable to increased temperature and decreasing water availability. Based on these empirical relationships, a 1 °C increase in mean annual temperature could cause a loss of 1900 kg soil organic C and 180 kg soil organic N ha-1 from the top 10 cm of soil over 30 years, but the decrease will be mediated by water availability.

(4). In the context of climate change, soil management practices must constrain the loss of SOM and decrease the vulnerability of soil organic C and N stock to loss. Management practices that minimize soil erosion and reduce evapo-transpiration may help offset C and N loss from the soils. The response of N dynamics to climate manipulation at the ecosystem scale is difficult to predict because of the complexity of plant-soil interactions.

(5). A medium-term field scale study into effects of simulated climate change on soil N mineralization was conducted in a calcareous grassland in southern England (Jamieson et al. 1998). The experiment utilized soil warming cables, automatic rain-shelters and a watering system to examine two climate change scenarios: warmer winters with summer drought, and warmer winters with enhanced summer rainfall. Results from control plots showed a strong seasonality of mineralization with highest rates in autumn and winter and lowest rates in summer. Water availability is the main constraint on microbial processes and plant growth. Unexpectedly, additional summer rainfall had no direct effect on N mineralization at the time of application (summer). The treatment did, however, significantly (~0.05%) reduce rates in subsequent autumn and winter months. In contrast, summer drought significantly increased N mineralization rates in autumn and winter. Winter warming similarly had no direct effect on N mineralization in winter but decreased rates in spring. The observed treatment effects resulted from changes in organic C and N input, in plant litter, resulting from the direct impact of climatic manipulation on perennial plant growth, death and senescence.

We also need clear understanding of climate change impacts on availability of P, K, S, Zn and other micronutrients in soils.

With the help of such information, we'll be able to formulate climate-smart strategy for soil fertility management.

thank you for  your invitation  Dr Srivastava for this high quality and  relevant question about the relationship between climate change and soil fertility. our colleagues had make a great contribution to this debate with informative answers. 

i can only add, that in my opinion , climate change can have a deleterious impact on the  rate of mineralisation of organic matter,  we have already since , this pattern , in arid and semi-arid region  ( low organic matter) , and now, it can affect, all the soil of the world , if the increase in CO2 emission continue through higher rate of Mineralisation

Carbon Sequestration in the Soil  can be a solution to mitigate climate change as it was eloquently point out in the Landmark paper in Nature by  Rattan Lal ( Soil Carbon Sequestration impact on Global Climate change and food Security, 2004).

King regards Louadj yacine.

Dr Srivastava, an excellent topic you have brought for discussion. Which of the soil properties considered to be most climate sensitive?

Paustian2016

Dear Anoop

Climate change is a fact, the difference is in its realization, and planning for it (management, research, infrastructures, Intelligentsia/intellectuals and counselling/creation of among stake-holders)

Today I went through a Newspaper article that I have attached.

climate change is a challenge for agriculturist now a days. Its severity depends upon area to area and place to place. The biggest challenge to be faced is temperature fluctuation, which will in turn effect plants, soil and other flora.

Anil Kumar, thanks for you response . Soil organic matter is , the major driver of entire nutrient and microbial dynamics , including the ability to moderate the negative consequences of climate change related consequences. Our concern is , how to moderate our strategies of soil fertility management ...?

So appreciative of such  a comprehensive response , Dr Kundu , and setting the whole discussion on such a positive front  . Some incisive facts  about the climate change scenario and our possible preparedness to combat the negative consequences of climate change . most of the studies are concentrated with regard to nitrogen ...overlooking other nutrients  . How are they going to behave ...is matter of great concern , especially in the light of climate change . Thanks Dr Kundu

How do you feel , soil C:N ratio as  a constant , it could increase or decrease as a consequential impact of climate change ..?

Let me respond to our other colleagues as well. Abhishek , you have rightly touched upon the epicentre of the discussion . this increase in CO2 leaves its impact along with hike in temperature as well  , and predisposes to acceleration in rate of minerlization , thereby , consequential loss of soil fertility , soil degradation ..and eventually unsustainability  in production ..Assuming constant inputs of carbon to soils from vegetation, different estimate predict that expected changes in temperature, precipitation and evaporation will cause significant change in organic matter turnover and CO2 dynamics. And ,, when we address the issue of soil fertility management , the key issues are : 

Integrated Soil Fertility Management (ISFM) is a set of practices related to cropping, fertilizers, organic resources and other amendments on smallholder farms to increase production and input use efficiency.

ISFM benefits food security and incomes, enhances yield stability in rainfed systems, and reduces greenhouse gas emissions from soils and fertilizers

making it of value to climate-smart agriculture.Nice information Abhishek...

Very interesting question and equally good discussion is in progress. My take on the question is how can we neutralise the impact of climate change on changes in soil physical, chemical and biological properties by bringing some innovative thinking in soil fertility management different from conventional soil fertility management ? 

Thanks  Louadj fro appreciating the discussion , and being a part of such a meaningful discussion . hope , we bring out some fruitful points with the collective involvement on this very important issue, the pivotal factor for sustainability of our agriculture . Yes , i do agree with you . If rate of mineralisation will increase leading to loss of carbon into the atmosphere , nitrogen as well find depletion  as volatilisation , thereby , causing cascading effects on whole lot of soil properties. Good response. 

Thanks Dr Deka and Dr Ghosh  for your valuable inputs. Dr Ghafoor , your attachment is in urdu , very few can read it ....so sorry ..cant respond further...

Hussain , i agree with you , it is the biggest challenge , and agriculture is most felt casuality . Our preparedness will transform these threats into opportunities , as you know , C4 plants are most benefitted with such CO2 rises.

Abhishek, your efficiency is well prooven . Som every useful attachments dear...

However , let me add some points about ISFM and mitigation of emissions of greenhouse gases : 

Practising ISFM offers different benefits to mitigate GHG emissions from agricultural systems. Fertilizer micro-dosing, disseminated under the first ISFM entry point, has been shown to significantly increase the recovery of N by crops (Sime & Aune, 2014; Kisinyo et al., 2015). Greater recovery of N fertilizers by crops, and retention of nitrate in soils, are two of the most important indicators for reduced emissions of nitrogen oxides in tropical farming systems (Hickman, 2011). Combining fertilizers and organic inputs also enhances fertilizer uptake and retention by balancing immobilization and release processes (Chivenge et al., 2009). A study in moist savannas of Tanzania demonstrated that maize crops retrieved between 16 and 25 kg N ha-1 from rotated greengram, pigeonpea and cowpea crops (Marandu et al., 2010). Substituting a urea input of 10 kg N ha-1 cuts emission from manufacturing by 20 kg CO2 (Bernstein et al., 2007). Based on default emission factors decreasing N fertilizer inputs by 10 kg ha-1 is expected to mitigate N2O emissions from soils by 60 kg CO2 equivalent ha-1 (Smith et al., 1997).

Combining fertilizers and organic inputs benefits the conservation and build-up of soil C stocks, hence mitigating CO2 emissions from soils. A study in Zimbabwe demonstrated that the practice of incorporating stover from maize crops reduced soil C losses by 10 to 20 tonnes of C per hectare over a period of 20 years (Zingore et al., 2005). Figure 5 presents results from 10 year trials across a range of soil types in Kenya showing that the soil organic C content was between 0.2 and 0.5% higher when fertilizers and manure were combined as compared to when exclusively fertilizers were used. Input of stover conversely didn’t sequester as much C in all of the soil type.

By aligning organic resource management with soil type, fertility level, climatic conditions and availability of resources the ISFM framework seeks to reach sustainable solutions for crop production at landscape farm and plot level.

Some facts for consideration...

This is a new subject for me. I have read some very good uploads by our learned colleagues and will continue to do so as the discussion is progressing.

How can we translate the climate change induced changes in soil properties much to the benefit of crops via higher productivity?

Dear Friends,

I wish to add some more inputs to the ongoing discussion. 

For arid and semiarid regions where droughts, soil acidity and degraded soils are the major constraints to agricultural production, we may require different kinds of management strategies to face the challenges of changing climate. In these regions, climate smart agriculture strategies will require synergistic provision of adequate water, nutrients and improved soil to support crop growth and minimize risk of crop failure.

Some water and nutrient management practices like harvesting of runoff water and organic matter in small pits, construction of stone bunds or vegetation strips combined with application of organic/inorganic sources of nutrients, and cereal-legume intercropping appear to be promising in these regions. Construction of stone bunds along the contours will facilitate harvesting of rain water and decrease runoff erosion of soil and organic carbon from the fields. Inclusion of drought tolerant legumes in the cropping system will promote biological nitrogen fixation and thereby improvement in soil fertility.

Such integrated soil, water and crop management practices will lead to improved soil fertility and soil moisture availability, and should be parts of the climate smart management of soil fertility in those regions.

Dr  Kundu, we usually notice soil alkalinity/salinity in abundance than soil acidity in arid regions. But I agree we need a climate specific soil- crop water management module for better climate smart management.  How does it differ from normal course of management? Where does climate mitigation strategies come into picture?

I'm sorry, Sikha. By mistake I wrote ''acidity'' in place of ''alkalinity''. Thanks for pointing out the same. Of course, to counter adverse impacts of increasingly unfavorable climate in those regions, soil and water conservation issues will assume greater importance, and we'll have to settle them first for effective nutrient management. I just wanted to make that point.  

How does climate smart technology differ from technologies developed in the light of climate change? What basic difference shall we address, friends.

Highly purposeful feedbacks from Dr Kundu , Dr Deka,  Dr Abhishek, Dr Singh.... 

Effects of higher CO2 on soil fertility, physical conditions and productivity

Higher atmospheric CO2 concentration, as discussed in subsequent chapters, increases growth rates and water-use efficiency of crops and natural vegetation in so far as other factors do not become limiting. The higher temperature optima of some plants under increased CO2 would tend to counteract adverse effects of temperature rise, such as increased nighttime respiration. The shortened growth cycle of a given species because of higher CO2 and temperature would be compensated for in natural vegetation by adjustments in species composition or dominance. In agro-ecosystems the choice of longer-duration cultivars or changes in cropping pattern could eliminate unproductive periods that might arise because of the shorter growth cycle of the main crop.

There will be adequate time to adjust to the changes since these are expected to occur over decades, rather than years or days as in all present experimental situations. This chapter deals with the effects of gradually rising CO2 concentrations as observed in the recent past and stipulated in simulation models that apply transient scenarios.

The increased productivity is generally accompanied by more litter or crop residues, a greater total root mass and root exudation, increased mycorrhizal colonization and activity of other rhizosphere or soil micro-organisms, including symbiotic and root-zone N, fixers. The latter would have a positive effect on N supply to crops or vegetation. The increased microbial and root activity in the soil would entail higher CO2 partial pressure in soil air and CO2 activity in soil water, hence increased rates of plant nutrient release (e.g., K, Mg, micronutrients) from weathering of soil minerals. Similarly, the mycorrhizal activity would lead to better phosphate uptake. These effects would be in synergy with better nutrient uptake by the more intensive root system due to higher atmospheric CO2 concentration. There is no a priori reason why the degree of synchrony between nutrient release and demand by crops or natural vegetation would be subject to major changes under high CO2 conditions.

The greater microbial activity tends to increase the quantity of plant nutrients cycling through soil organisms. The increased production of root material (at similar temperatures) tends to raise soil organic matter content, which also entails the temporary immobilization and cycling of greater quantities of plant nutrients in the soil. Higher C/N ratios in litter, reported by some workers under high CO2 conditions, would entail slower decomposition and slower remobilization of the plant nutrients from the litter and uptake by the root mat, and would provide more time for incorporation into the soil by earthworms, termites, etc. Higher soil temperatures would counteract increases in 'stable' soil organic matter content but would further stimulate microbial activity.

In all experimental situations, whether chamber-type or free-air enrichment, CO2 increases are rapid or sudden, often to double ambient concentration, sometimes higher. The consequently rapid increases in soil organic matter dynamics and soil micro-organisms may cause temporary competition for plant nutrients. These temporary effects have on occasion been reported as negative factors affecting plant response to elevated CO2 However, increased organic matter dynamics and microbial activity in soils are positive for the soil-plant system when CO2 concentrations rise gradually over decades, as currently and in the recent past. Future experiments could be set up to compensate for the temporary effects caused by the suddenness of the CO2 increase, for example by artificially higher soil organic matter contents estimated to be near equilibrium with each stepwise higher CO2 concentration, in a range between 350 and 600 ppm.

Increased microbial activity due to higher CO2 concentration and temperature produces greater amounts of polysaccharides and other soil stabilizers. Increases in litter or crop residues, root mass and organic matter content tend to stimulate the activity of soil macrofauna, including earthworms, with consequently improved infiltration rate and bypass flow by the greater number of stable biopores. The greater stability and the faster infiltration increase the resilience of the soil against water erosion and consequent loss of soil fertility. The increased proportion of bypass flow also decreases the nutrient loss by leaching during periods with excess rainfall. This refers to the available nutrients in the soil, including well-incorporated fertilizers or manure, but not to fertilizers broadcast on the soil surface. These are subject to loss by runoff or leaching.

Based on exerpts from ROBERT BRINKMAN AND WIM G. SOMBROEK

Land and Water Development Division. FAO, Rome, Italy.

Lets debate further  on the points raised by Dr  Anil Kumar Singh , which are so relevant in the context of on-going discussion .

Let me initiate some discussion friends...

I am adding an excellent document by Prof Swift entitled  SOIL FERTILITY AND GLOBAL CHANGE . The summary of the document is furnished below: 

Soil is the  largest terrestrial pool of carbon, nitrogen and sulphur, and is intimately involved in the main fluxes of these important greenhouse elements

between land and atmosphere. Soil is also a fundamental resource on which

human populations are dependent for food, fuel and fibre. Land use shifts and

their sustainability are an important part of Global Change, and it is through the

response of the plant-soi1 system that climate change will have its main impact

on humankind. Furthermore, it is in the tropics that the demands of developing

human populations are/most tightly linked to climate- and mil-determined limits.

Paradoxically, it is in this zone and on these topics that Our capacity to respond

scientifically is weakest.

a)That the IGBP( International Geosphere-Biosphere Program to study interactive physical , chemical and biological  processes regulating earth system ) should initiate a detailed study of the consequences of CO2, and climate change on soil biological processes, including elemental and water fluxes between soil and atmosphere, utilizing the TSBF ( Tropical Soil Biology and Fertility Program , initiated in 1984  by international Union of Biological Sciences and UNESCO to look into the role of biological processes in maintainance of soil fertility) concepts and expertise as captured in the CENTURY model.

b) The IGBP and TSBF collaborate to develop a programme to examine the

effects of global change on the diversity, populations levels, distribution and

behaviour patterns of key functional groups of soil organisms with particular

reference to effects in marginal distribution zones.

c) The IGBP and TSBF work together to develop ecosystem models depicting the synchronization of vegetational and soil processes and examine the effects of differential rates of change in response to globai change with respect to vegetational distribution and use potential particularly in marginal or transitional environments.

d) The IGBP and TSBF develop a joint study, by means of modelling and field experimentation, of the influences of change in land use and climate change on the long term storage of carbon and other nutrients in soil, and in particular seek means of increasing the sequestration of carbon in soil by suitable ameliorative action.

e) The IGBP should assist in incorporating studies of sulphur dynamics and denitrification into the TSBF programme.

f) The IGBP should consider the development of selected TSBF intensive study sites as part of their network of Regional Research Centres and Regional

• The document is enclosed for further reading ...

Why do we discuss most of the information with respect to soil N only when we talk of climate change induced changes in soil fertility. Is it because of better immunity of other nutrients exposed to climate change..?

Dear Sikha,

your observation is right. Much of our soil fertility research has so far been heavily biased in favour of nitrogen, with relatively little attention paid to other nutrients. Other nutrients are not at all immune to climate change. It is due to lack of information available, we are discussing less on other nutrients. I hope some of us will share their ideas/ available information on the subject (climate change impact on availability of other nutrients in soil) in this forum. Thanks for pointing out the missing links of our discussion.   

Dr. Abhishek Raj has explained terms nicely. II appreciate.

Excellent feedbacks Abhishek , and so pertinent in the context of whole discussion in progress . i would request  you to see some  more finding of Smartsoil project  referring nutrients  other than nitrogen. Dr Deka was dead right and fully endorsed by Dr Kundu . Taking some more clues from review by St Clair and Lynch ( Plant Soil 2010) : 

Nutrient impoverished soils contribute to human malnutrition in two important ways. First, they reduce crop yields, causing food scarcity that results in protein energymalnutrition.Second,crops produced on nutrient poor soils typically have low tissue concentrations of trace elements.Human populations whose diet primarily consists of staple cereal crops (primarily maize, rice, wheat, sorghum, and millet) may meet their protein and energy demands but often suffer micronutrient deficiencies. It is estimated that of the world’s human population, 60–80% are Fe deficient, >30% are Zn deficient, 30% are Iodine deficient and about 15% are Se deficient (White and Broadley 2005). The overwhelming majority of people that suffer from micronutrient deficiencies live in developing countries (Kennedy et al. 2003). 

If we are somehow able to clear this first hurdle and increase crop yields and nutrient availability by overcoming soil limitations, global climate change also looms large in determining food sufficiency and quality in the 21st century (Rosenzweig and Parry 1994). Evidence suggests that due to high vulnerabilities and limited resources, developing countries may have limited capacity to implement adaptation measures to achieve food stability in a warmer climate (Kates 2000; Mertz et al. 2009). It is well documented that climate warming, and changes in global precipitation patterns, particularly drought, are already affecting crop production in developing countries (Pandey et al. 2007; Barrios et al. 2008). An important but poorly understood effect of climate change is its influence on soil fertility and nutrient acquisition and utilization by plants (Lynch and St Clair 2004). 

Thanks Dr Ghafoor for being a part of this discussion..

Some issues..

Dr Kirti , i fully agree with your remarks. No single strategy will t be able to tranform our nutrient deficient soils climate smart . Thats a very valid point , how long  a RDF  worked out  for a specific crop for a specific soil type under a specific agro-ecological/agro-pedological region ( collectively we can call it biophysical and socioeconomical condition ) through multilocation experimentation stands out to fulfill the nutrient demand ....under changing climate ...??

Yes it is a valid point raised by Kirti about the validity of optimum fertilizer doses in terms of time limit in relation to climate change.

Thanks Abhishek for keeping the discussion so live and so fruitful...no words ...

Differences in the pattern of horticultural production in the two  contrasting areas are the product of factors such as soil type, proximity to markets, communications network, and grower expertise, in addition to climate. There is little experimental evidence from which to assess the specific contribution of climate in determining crop distribution but some deductions may be made on the basis of the change in cropping pattern with latitude.

Changes in production due to climate change will also critically depend on crop management, such as the type and levels of applied irrigation and  fertilization. Recent experiments have shown that cropresponse to elevated CO2 is relatively greater when water is a limiting factor, compared to well- watered conditions (Chaudhuri et al. 1990, Kimball et al. 1995). The contrary is true for nitrogen applications: well fertilized crops respond more positively to CO2 than less fertilized ones (Sionit et al. 1981). Finally, CO2 will affect differently C3 (e.g. wheat, soybean, citrus) and C4 plants (e.g. maize, sorghum, plus several important agricultural weeds), as the latter group is less responsive than the former to increased CO2 levels in the atmosphere (Rosenzweig & Hillel 1998). the importance of crop response to elevated CO2 under climate change. It is still uncertain whether CO2 fertilization will be as strong in agricultural fields as suggested under controlled experiments. At simulation sites in the Great Plains, for instance, maize yield changes ranged between –30 and +20% compared to the present, depending on the assume strength of the simulated CO2 response.

We need indepth analysis on : 

*  Attempts to relate crop yield to climatic conditions must take account of the

wide variability of responses between species.

*  Weather conditions at specific developmental stages may exert a greater

effect on yield than the conditions which determine growth rate.

*  Indirect effects of climate on plant growth and development are potentially

as limiting as direct effects.

*  As crop growth and yield are strongly influenced by plant population,

climatic factors determining germination and emergence may significantly

affect subsequent crop growth rate.

Some thoughts friends....

Current nutrient management recommendations are based on an understanding of crop-specific needs for achieving expected yields and soil-specific nutrient supply characteristics. To what extent does our existing knowledge remain useful under a changed climate? Addressing this question requires an assessment of the potential for global climate change factors to influence the physiological efficiency (PE) of nutrient use within the plant and to alter the availability of nutrients in soil and their transport through soil and across root membranes.Plants accumulate nutrients from the soil solution pool, and nutrients must be in solution to be mobile in the soil. In the absence of roots, steady-state solution-phase concentrations of nutrient ions are controlled by adsorption–precipitation and desorption–dissolution reactions between nutrients and the surface complex of soil, mineralization and immobilization for solutes of organic origin and additions from fertilize. While few, if any, studies have examined impacts of elevated CO2 on solution-phase concentrations of nutrients such as K whose availability is not strongly controlled by biological activity, theory suggests that any impacts will also be indirectly mediated by temperature and moisture changes.

Nutrient acquisition is closely associated with overall biomass and strongly influenced by root surface area. When climate change alters soil factors to restrict root growth, nutrient stress will occur. Plant size may also change but

nutrient concentration will remain relatively unchanged; therefore, nutrient

removal will scale with growth. Changes in regional nutrient      requirements will be most remarkable where we alter cropping systems to accommodate  in

ecozones or alter farming systems to capture new uses from existing systems.

For regions and systems where we currently do an adequate job managing

nutrients, we stand a good chance of continued optimization under a changed

climate. If we can and should do better, climate change will not help us ( Source : Brouder eta l.2008. Physiologia Plantarum 133: 705-708).

The reduction in wetland water table height that could be anticipated from current climate change models was simulated within the laboratory using cores of peat-soil from a riparian wetland. The manipulation increased the rate of release of many solutes including nitrate (1250%), sulphate (116%), dissolved organic carbon (37%), sodium (66%), chloride (65%), iron (168%) and Mg (16%). Calcium was the only solute to show a lower rate of release following the simulation (- 26%). These changes have major implications for the use of constructed wetlands in ameliorating water quality.The study suggests that without suitable design safeguards, wetlands may only represent a temporary solution to water quality problems. In the future, climatic change could reverse their beneficial effects. (Source : Freeman eta l. 1993 , Ecol. Eng. 2: 367-373).

Some thoughts reproduced ... 

Nice to see some discussions on nutrients other than Nitrogen. We need more discussion on other nutrients. No one responded on how optimum fertilizer doses respond to climate change over time.

Dear Sikha,

May I hereby provide some information on climate change impact on phosphorus availability in soils? Climate change has significant influence on soil P availability. Increasing temperature tends to increase P mineralization of organic matter. Temperature increases by 5°C have been found to double the colonization of roots by mycorrhiza. Nitrogen mineralization was found to increase by an average 48% due to temperature increases by 0.3°C to 6.0°C. Larger amounts of N stimulated phosphatase exudation and plant P uptake, which may further increase soil P availability. Such a development would reduce plant biodiversity and promote the growth of ruderal, fast-growing species. For sustainable agriculture, increases in soil P relative to other factors limiting plant growth have to be prevented to ensure large plant biodiversity. 

I hope you find this information useful, and suggest all my friends to go through the following article for further details:

Nicole Wrage et al. (2009) Phosphorus, plant biodiversity and climate change. Pages 147-169 in Sociology, Organic Farming, Climate Change and Soil Science. Springer Netherlands. 

Interesting information Dr Kundu.

Thanks Dr Anoop sir for initiating the discussion and thanks to other colleagues including Dr Kundu sir, Dr. Abhishek sir and all for the important literray and scientific inputs. Like Dr Nazir Hussain sir, we could learn so many new things from all of you. We would like our colleagues to have a look on the following few points and if it's worth discussing, to give their valuable inputs.

Regarding fertilizer application, would it perform better applying complete fertilizer (N-P-K or N-P-K-micronutrient) instead of single nutrient fertilizer. Besides, the fertilizers need to have controlled release of nutrients. We could come across few literature reporting works on nutrient release from fertilizer in response to change in soil pH, redox potential, water stress, temperature, root plasticity etc. Is there scope to collaborate with  physiologists, plant breeders, fertilizer technology and others, and would it help in climate change agriculture??

The importance and significance of SOM are very well covered and discussed. At the same time is there need to focus on preserving/maintaining optimum diversity and population of microbe in soil. Microbe-mediated nutrient release from SOM or mineral source had already been utilized. Is there scope to harness the microflora more towards effective nutrient management???

Dr Kundu , i appreciate , it is good piece of information . 

Some thought provoking points Dr Nilay , you have added through your response. Somewhere , we have discussed this issue earlier as well, RDF needs to re-defined in terms of not NPK alone  but NPK plus micronutrients. concept of slow release or controlled release of inorganic fertilizers   has shown their worth in a number of crops and under diiverse conditions , but somehow has not gained that amount of popularity , it deserves. To counter that , we started combination of organic and inorganic fertilizers , with the same philosophy of extending the period of nutrient availability  in a growing season . Yes , it is a very good point  to maintain soil microbial diversity , and probably that way , it those microbes will moderate the effect  of climate change and at  the same time , labile nutrient pool of soil will also be boosted , since these microbes are known to act as very strong nutrient sink. In this context , Dr Nilay , floor management through cover crops or green manuring or introducing a cropping sequence having pulses or some legumes have also  aided  a world of good to the  causes of soil microbial diversity , the invisible managers of soil fertility.

Yes , it is very much possible to harness much better dividends than what we harvest today through conventional practices , using rhizocompetent  ( vis-a-vis plant endophytes) microbes as a part of effective nutrient management . Please have a look  at the research papers published on nutrient management using microbes and their source , mostly it is non-native source , thats the single most glaring reason of our inability to enforce an effective nutrient management program. Hope , you agree with my statements...

Dr Nilay, your points of concern are very valid. Dr Srivastava, you have ably responded. Let me raise a very basic question, how long a RDF can withstand against ongoing climate change ? 

What should be the period of validity of RDF with respect to crop ?

Dr Nilay , Dr  Shirgure , and other friends . Let me share with you our own experiences in citrus. We worked out the schedule of  optimum doses of Nagpur mandarin on Vertic Ustochrept soil  during 1990-1995 , and the same optimum doses after 20 years stands out to be incorrect on the same crop and same soil with soil fertility hardly undergone any significant change so far. the basic reason was the presence of 1.5-2.0 0C higher temperature at fruit set stage compared to baseline temperature of 1990-1995, with the result , we had to apply 20% higher K to achieve the same yield expectancy , off course , without affecting the fruit quality. Therefore , both of you are so right in your own context...and i endorse these points with full strength..

Dr. Kumar! I agree to your view point. We have to think all about these consideration.

Dr Anoop,

I endorse your statements, and we earlier discussed few things during our discussion on cover crops, nutrient management.

Dr Anoop and Dr Shirgure,

Regarding the validity of RFD, your observations, statements are appreciated. Besides, sometimes the response of crops to higher RDF may be due to adulteration of the fertilizer (commercial) product, could it be??? Once, we analysed (off the record) the products being used by the farmers and found much lower contents of P and K than the prescribed ones.

Thanks Dr Nazir . This is how crop phenology vis-a-vis nutritional physiology work in tandem  over a period of time . And , this is the reason , we need to look at the utility of RDF in the context of climate change , if we are able to  tailor the fertilizer requirement  as  per  changing crop phenology in the light of climate change , our fertilizer application will become more climate smart , and RDF more in tune with climate change.?

Dr Nilay , well taken your viewpoint , but such things do not happen by and large .We are more inclined to normal fertilizers where we have the genuine fertilizer quality .  In universities , we have seen , once RDF comes out for a crop , it continues for years and years without any periodical revision , and above all you have climate change issues , changing the entire phenology of crop , that fertilizer application instead of demand driven , becomes just a practice of formality ..Such issues , we need to look into more seriously ...

very good question, few points i wish to putforth:

1. Rapid changes in land use and land cover change alongwith climate change needs to e plugged in

2. Carbon sequestration within the root zone layer is important

3. Nutrients management in toto is quite complex and far beyond quantification, although most of the approaches tend to be qualitative or empirical

4. Inter- and intra-climatic variations are quite large or wide

5. Inter-crop and inter-varietal differences to inputs and climatic variability

6. Rainfall changes play an important role for nutrients management, specifically in dryland and rainfed regions

7. Fertilizer management needs to be linked to attainable yields, under climate change and climatic variability

8. Soil health, in particular soil biological health coupled with climatic variability/climate change, needs to be linked to nutrients management

9. Need of climate smart agriculture for knowledge/decision dissemination is required

10. possibly a DSS with effective use of crop models, technical coefficient generator, thumb rules and experts' judgement

11. issue is quite complex, far beyond publishing research papers on specific aspects, possibly an integrated approach

regards to all and thanks Anoop for linking me in particular with this question

Good points by Karla.

A set of good management practices based on application of ecofriendly nutrients sources preferably from organic sources, biofertilizers, green manuring, maintain soil biological health, need based nutrient application are the components of climate smart fertility management.

Dear Malhotra, the components of climate smart fertility management you mentioned are all ideal. However, the question is that can we meet whole nutrient requirements of crops through all these without chemical fertilizers.

Some very nice points Dr Kalra .They would go long way to keep the discussion live . unfortunately , these decision support systems relating climate change predictability hold a much lesser utility in the context validating with ground truth , and when it comes to soil related changes , the predictability declines still further, Rest of your points are worth considering .

Thanks Dr Malhotra  for flagging the combination of organic manures , inorganic fertilizers and microbial inoculants , which holds much better  promise under all conditions , whether or not affected with climate change . More important here is to develop the microbial load of the soil , which could lessen the temporary loss in nutrient flux in response to sudden change in climate including the extreme events. I agree with the comments of Dr Nazir . We can start with some starter amount of inorganic fertilizers as fillip to microbial proliferation , which in combination with organic manures , could later  display better resilience against any possible nutrient mining or loss in soil fertility..?

Yes, Dr. Kumar's suggestion is OK and will help a lot in keeping crop production sustainable.

Soil nitrogen (N) availability is one of the main factors limiting crop production in many agricultural systems. The possible impacts of climate change on N losses associated with agricultural production are not well understood. Dynamic simulation models of the soil/crop/atmosphere system are tools that can be used to assess N losses associated with crop production, identify possible management alternatives to improve N use efficiency in crop production and provide insight into the impact of future climate on agricultural N use and N losses. Melkonian is investigating the role of N and water in crop and soil systems by applying dynamic simulation modeling combined with field ex. Goals of Melkonian’s research include assessing the yield potential of different land use categories (e.g., current crop land, marginal or underused land) for crops, including bioenergy crops, testing alternative strategies for nutrient and water management in agriculture to reduce negative environmental impacts, using dynamic simulation modeling to investigate yield gaps in crop production and using dynamic simulation models of the soil/plant/atmosphere continuum to design more targeted and fruitful experimental strategies. Such models are leading to the development of tools such as Adapt-N, which helps farmers determine the most efficient nitrogen fertilizer sidedress rate for corn. Developed in collaboration with the Department of Earth and Atmospheric Sciences, the Northeast Regional Climatic Center, and the Center for Advanced Computing, Adapt-N accounts for changes in soil N due to early season weather and adjusts the in-season N recommendations accordingly. ( Source : Jeffrey Melkonian). 

The indirect effects via shifts in plant-soil microbe and soil microbe-microbe interactions are less acknowledged they have the potential to mediate important processes such as plant chemistry, plant community composition, and mineralization rates much like shifts in other ecological interactions alter important functions. Classen et al. (2015, Ecosphere, 6: 1-21) raised following ten questions about the subject entitled soil- microbial-plant interactions : 

1. What degree of change in the direct and/or the indirect effects of climate change on microbe-microbe or plant-microbial interactions are relevant for ecosystem functioning?

2. How stable are microbial communities through time? How frequently should they be sampled to capture accurate and meaningful information about their composition and function?

3. At what scale might microbial dispersal limitation begin to matter for ecosystem function and how quickly will microbes adapt to changing climate?

4. Are the indirect effects of climate change on communities as important as the direct effects for ecosystem process rates and carbon feedbacks?

5. Will the asynchronous responses of root, shoot, and microbial phenologies to climate change be important drivers of plant community shifts and ecosystem productivity?

6. At what spatial and temporal scales should we measure microbial processes and interactions at in order to understand how climate change will influence microbial diversity, community composition, and function at ecosystem and global scales?

7. Will climate change alter the direction of plant-microbe interactions from positive to negative or vice versa and what will the consequences be for ecosystem function?

8. Are there tradeoffs between plants maintaining symbionts that provide short-term (e.g., nutrient acquisition) vs. long-term (e.g., pathogen protection) benefits? How will climate change affect specialist symbionts?

9. How can we scale up plant-microbial interactions given that plants and microbes function on different spatial and temporal scales? At what scale (e.g., root-soil interface) should we be measuring plant-microbe interactions?

10. How do we standardize methodologies so that microbial communities are comparable across studies and over time?

Highly relevant issues....

Dear Dr. Anoop

The topic opened for discussion is most relavant to present situation. Good discussions are going on

I would like to add that soil organic matter (SOM) is most important component gets affected by climate change factors. If global  temperature increased will decrease the SOM due to mineralization and some thermophilic organisms decompose SOM at faster rate than normal. N is most vulnarable plant nutrient. Organic farming practices, like Seed treatment with Bheejaamruth, soil application of Jeevamrutha and panchagavya will add numerous beneficial micro organisms to the soil and they will be useful in fixing atmospheric N, solubilizing fixed P and enhances soil microbial activity. The farmers at Northern Karnataka realized stabilization of yields and better soil fertility with organic farming practices. i hope this OF practices will serve better for climate smart soil fertility management. Because it influence several biological process in the soil rather than a meagre nutrient source.

Dear Dr. Srivastava,

I wish to share some recent research results of Wang et al. (2016) that may be used to develop climate smart micronutrients (Fe, Mn, Zn and Cu) management strategy for crop production:

Effect of CO2 enrichment (upto 500 ppm) and plant canopy warming (by 2oC) on micronutrient concentrations both in soil and plants were studied in an open field experiment, and the accumulated uptake by wheat harvest was assessed.  

(1) The availability of Fe, Mn, Cu, and Zn in soil under CO2 enrichment  increased by 47.7, 22.5, 59.8, and 114.1 %, respectively. Warming increased the availability of Fe, Cu, and Zn in soil by 60.4, 23.8, and 15.3 %, respectively. 

(2) The increase in soil micronutrient availability did not always lead to the increase in micronutrient uptake. The element types and crop growth stage affected the uptake of micronutrients by wheat under CO2 enrichment and warming.

(3) The enrichment of CO2 and warming had significant effects on micronutrient uptake by wheat. The enrichment of CO2 decreased the concentration of Fe by 9.3 %, while it increased the concentrations of Mn and Zn by 18.9 and 8.1 % in plant shoot, respectively. Warming increased the concentration of Fe and Cu by 24.3 and 7.6 % in plant shoot, respectively.

(4) Additionally, CO2 enrichment decreased the translocation of Fe and Zn by 25.3 and 10.0 %, respectively, while warming increased the translocation of Fe, Mn, Cu, and Zn across stages.

These results indicated that CO2 enrichment and warming would improve availability of some micronutrients in soil and their uptake by wheat. However, it is still not clear whether a net removal of micronutrient through crop straw harvest would occur under CO2 enrichment and warming.

Ref: Wang, J. et al. (2016) J Soils Sediments. doi:10.1007/s11368-016-1464-8.

highly appreciate your answer @Abhishek Raj. Thanks for sharing such a useful information.

Dear Dr. Srivastava, Sikha and my all other RG friends,

I wish to share some recent research results that may be useful to develop climate smart micronutrients (Fe, Mn, Zn and Cu) management strategy for crop production:

Effect of CO2 enrichment (upto 500 ppm) and plant canopy warming (by 2oC) on micronutrient concentrations both in soil and plants were studied in an open field experiment, and the accumulated uptake by wheat harvest was assessed.  

(1) The availability of Fe, Mn, Cu, and Zn in soil under CO2 enrichment  increased by 47.7, 22.5, 59.8, and 114.1 %, respectively. Warming increased the availability of Fe, Cu, and Zn in soil by 60.4, 23.8, and 15.3 %, respectively. 

(2) The increase in soil micronutrient availability did not always lead to the increase in micronutrient uptake. The element types and crop growth stage affected the uptake of micronutrients by wheat under CO2 enrichment and warming.

(3) The enrichment of CO2 and warming had significant effects on micronutrient uptake by wheat. The enrichment of CO2 decreased the concentration of Fe by 9.3 %, while it increased the concentrations of Mn and Zn by 18.9 and 8.1 % in plant shoot, respectively. Warming increased the concentration of Fe and Cu by 24.3 and 7.6 % in plant shoot, respectively.

(4) Additionally, CO2 enrichment decreased the translocation of Fe and Zn by 25.3 and 10.0 %, respectively, while warming increased the translocation of Fe, Mn, Cu, and Zn across stages.

These results indicated that CO2 enrichment and warming would improve availability of some micronutrients in soil and their uptake by wheat. However, it is still not clear whether a net removal of micronutrient through crop straw harvest would occur under CO2 enrichment and warming.

[Ref: Wang, J. et al. (2016) J Soils Sediments. doi:10.1007/s11368-016-1464-8].

Drs. Abhishek Raj  and Dilip Kumar Kundu has given good direction and means to further debate and discussion on the subject question raised  by Dr. Anoop Kumar Srivastava .I am sure the discussion will serve as food for thought for the young scientists in the discipline of Soil Sciences.

Thank you Raj for uploading excellent literature.

Dear Dr. Anoop

Thank you for sharing useful information and discussion.,Climate change is one of the most serious environmental threats facing mankind worldwide adequate provision for irrigation, drainage, weather forecasting and other agricultural technology . It affects agriculture in several ways, including its direct impact on food production. Climate change, which is attributable to the natural climate cycle and human activities, has adversely affected agricultural productivity in the world. The soil management in the context of climate change. It begins with an overview of some of the principles of soil health and the way soils interact with the atmosphere and with terrestrial and freshwater ecosystems. Sustainable soil management options are presented as “win-win-win” strategies that sequester carbon in the soil, reduce greenhouse gas (GHG) emissions and help intensify production, all while enhancing the natural resource base. The module also describes practices that contribute to climate change adaptation and mitigation, and build the resilience of agricultural ecosystems.

1.       Knowing the status and condition of soils and their properties is fundamental for making decisions about sustainable soil management practices that contribute to climate-smart land use.

2.        Soils that have been degraded are at much greater risk from the damaging impacts of climate change. Degraded soils are vulnerable due to serious losses of soil organic matter (SOM) and soil biodiversity, greater soil compaction and increased rates of soil erosion and landslides. In addition, land degradation is itself a major cause of climate change.

3.        Management practices that increase soil organic carbon (SOC) content through organic matter management rather than depleting it will bring win-win-win benefits. These practices will maintain productive soils that are rich in carbon, require fewer chemical inputs and sustain vital ecosystem functions, such as the hydrological and nutrient cycles.

4.        The sound management of the interrelations among soils, crops and water can increase SOM, improve the soil’s capacity to retain nutrients and water, and enhance soil biodiversity. Integrated management practices can create optimal physical and biological conditions for sustainable agricultural production (including food, fibre, fodder, bioenergy and tree crops, and livestock).

Climate change is perhaps the most serious environmental threat to the fight against hunger, malnutrition, disease and poverty in many country, mainly through its impact on agricultural productivity. 

Traditional agricultural practices; Trade Liberalization and Market Development;  Policies, Institutions and Public Goods; and Information and Human Capital. Both government and the private sector, which should drive the sector through consistent policies, robust funding and infrastructure development, have failed to accord this problem the priority it deserves.

Sustainable intensification’  and ‘climate-smart agriculture’ (CSA) are closely interlinked.The main difference is the focus in CSA on outcomes related to climate change adaptation and mitigation.SI contributes to adaptation: building ecosystem services, increasing farm incomes.SI is crucial for reduced emissions per unit of output, through lower direct emissions and less land cover change.CSA and SI are only part of a multi-pronged approach toward global food security.

Given the need to increase production in many developing countries, agriculture's GHG emissions are likely to increase, largely due to continuing expansion in livestock production, fertilizer use and land cover change

CSA case studies showing the role of sustainable intensification

1.        Banana-coffee intercropping

2.       Livestock systems intensification

3.       Livestock diet intensification through agroforestry.

4.       Stone bunds and zaï pits in the Sahel

SI and CSA are closely interlinked concepts. The main difference is the focus in CSA on outcomes related to climate change adaptation and mitigation. SI is crucial to both adaptation and mitigation. All cases of CSA invariably turn out to be cases of SI. A climate justice perspective necessitates action to assist resource-poor farmers who are most affected by climate change but have contributed least to it, so that developing countries can enhance their food security and speed their economic growth. Actions taken to improve food security and help farmers adapt may often have significant mitigation co-benefits, but they may also have higher upfront costs (e.g. extra labour costs). Identifying appropriate ways to incentivize the uptake of climate smart alternatives is a key priority. In many countries agricultural policy is inextricably linked with economic support for rural economies. There are increasing possibilities for low-income countries to orientate production along pathways that are both more sustainable and more productive. Research and development partners have a key role to play in identifying and promoting climate-smart practices that strengthen rural communities, improve smallholder livelihoods and employment, and avoid negative social and cultural impacts such as loss of land tenure and forced migration. In many developing countries the design and operation of agricultural support could be radically improved, and SI and CSA goals need to be developed within this broad policy context.

The survival, development, protection and participation of children are all implicated in a climate-changing world. Deprivations, such as poor nutrition, are irreversible by the age of 24 months and have lifelong cognitive, physical and reproductive repercussions for children. The UNICEF climate change study used the UNICEF conceptual framework for child malnutrition (1990) to examine the causal links between societal, household and immediate influences on child malnutrition.

There exists a very few households which are selfsufficient in terms of food security, even though, the food system appears to be simple with a farmer consuming his own produce. The system has capacity to change and modify with the concurrent climatic, economic and social structure and is increasingly complex.

The food security involves following components:

1.       Availability: Adequacy of food supplies in terms of quantity, quality and variety

2.       Access: Affordability and allocation of food as per preferences of individuals.

3.       Utilization: Safe and sufficient food to meet physiological requirements of the individual such as health and nutritional values .

4.       Stability: The ability to consistently obtain food over time.

There might be physiographical, climatological, crop culture management, crop genetic, nutrient quality and quantity variables. One could apprehend either excess or shortage or exact input which is impossible to quantify. Will it be wise to allow the field physic-chemical-cultural and biological environment to interact and compensate mutually for a sustainable production? For example loss due to contour or slope or drainage may be prevented by immobilization, physical trenches or admixture of high quality and low quality organic matter along with promotion of various functional soil biota associated with simultaneous mineralization and immobilization.

The recommendations about the recommended doses of fertilizers emerge either from research trials at standard experimental field or from farmers field , will it make such distinctive change in amount of nutrients to be applied in field. then , what is the relevance of these two concepts of developing the information about recommended doses of fertilizers . But , more interestingly , we need to fine tune such recommendations at the filed level through some kind of ready reckoner to suit at various levels of soil test ratings.recommendations  for each farmer or farm is very difficult.As you rightly pointed out we give recommendations based on soil test value of a particular field for normal but some what high yield  achievable  in a  particular area.If the farmer has limitations of irrigation water,availabilty of sufficient manure and money to purchage the fertilizers then the extension worker or incharge of soil testing lab may have to modify the recommendation.To achieve 60% or 80% of the targeted yield, the recommendation may also be proportionately lowered .

Identifying, investigating, and explaining health problems at the population level remain classic public health responsibilities—the community equivalent of a physician’s diagnostic workups of patients. These functions, which flow directly from the previous task (monitoring health status), are well established in public health. However, climate change will require enhanced diagnostic and investigative capacity throughout the health system. For example, ecological changes may alter traditional vector-borne disease dynamics, possibly redefining animal hosts, vectors, and disease outcomes at the local and regional scales. Techniques that help assess health vulnerability to climate change have been proposed and offer a proactive approach to diagnosis. The capacity of public health laboratories must be enhanced to allow rapid diagnosis and reporting of diseases that are reintroduced or alter their distribution.

Some of the basic concepts , we need to introduce  with regard to soil fertility management organically . Use of green manure crops as a part of floor management , introduction of legumes  as part of a cropping sequence , organic manures/composts loaded with native isolates of microbes, including AMFs, minimum tillage , laying maximum emphasis on rhizosphere environment buildup,  ...and most important of all, you need to develop an effective via media to diagnose which nutrient and what stage of crop is missing from rhizosphere , how much  and which source , we need to supplement organically . 4R concept here also operates within organic agriculture as well...

https://www.researchgate.net/post/How_can_we_fine_tune_the_recommmended_doses_of_fertilizers_at_the_field_level?_tpcectx=profile_questions

https://www.researchgate.net/post/What_are_various_soil_fertility_management_strategies_that_are_recommended_for_an_organic_farmer?_tpcectx=profile_questions

Article Climate Change, Food and Nutritional Security: Issues and Co...

One should not ferget the role of SOM in climage smart agril.

 To quantify the impacts of climate change on horticultural crops, we need detailed information on physiological responses of the crops, soil-plant relationship, effects on growth and development, quality and productivity. The various impacts need to be addressed in concerted and systematic manner in order to prepare the horticulture sector to face the imminent challenges of climate change. The rise in temperature would lead to higher respiration rate, alter photosynthesis rate and partitioning of photosynthates to economic parts. It could also alter the phenology, shorten the crop duration, days to flowering and fruiting, hasten fruit maturity, ripening and senescence. The sensitivity of individual crop to climate change depends on inherent tolerance and growing habits. Indeterminate crops are less sensitive to heat stress conditions due to extended flowering compared to determinate crops. In tropical regions even moderate warming may lead to disproportionate declines in yield. In high latitudes, crop yields may improve as a result of a small increase in temperatures. In developing countries, which are predominantly located in lower latitudes, temperatures are already closer to or beyond thresholds and further warming would reduce rather than increase productivity. The impact of climate change is likely to differ with region and type of the crop and edaphology.

Thanks Dr Chandrashekara for your response , i do agree with you  about the  central role of SOM in regulating the microbial abundance in the soil , thereby , moderating the negative consequences of climate change . but , i am still to get a response , how climate change related issues are different than the climate smart concept , tactically , where do they differ with each other....?

Dr Kundu so sorry for my delayed response on your excellent feedback, undoubtedly one of the finest feedbacks so far and least discussed issue. Do you feel , an increase in CO2 enrichmnet in soil and  warming  both generated an increment in availability  and uptake of Fe, Mn , Zn and Cu by crops , are simply triggered by some favorable effects on soil microbial population  including reorientation in structural  or functional diversity of different microbial communities..? interestingly , despite increase in availability of micronutrients  and their uptake ,  their effective utilisation is an issue under such elevated climate change scenario..? What shall be done to moderate this issue ..? Do you feel, some varietal intervention or  different growth regulators role to be brought in here..?

Thanks, Dr. Srivastava,

for your belated but valuable response. You are right in assumption that increased concentration of CO2 and elevated temperature may have greater impact on microbiological than chemical properties of soil health.  Another observation that increased availability of micronutrients in soil was not always reflected in plant uptake, needs further research to understand the reason. You have given an excellent idea: to study if crop genotypes/ varieties differ in their ability to utilize micronutrients available in the soil under changed environment. This opens up a new opportunity for the micronutrient researchers to resolve the issue.

Abhishek , your pinching responses give so much fillip to discussion and so m uch depth as well. Let me add something :  

Climate change induced  change in redox-driven redistribution of Fe may place a further abiotic constraint on nutrient retention by plants. In combination, these data indicate that the effects of soil aging on plant uplift and retention of nutrients differ markedly with precipitation, as a potentially fruitful area for future research( Porder and Chadwick 2009, 90: 623-636).utrient loading s s another phenomenon  influenced buy cliamte chnage with distinctive seasonality . Nutrient loading slightly decreased in April and late summer for several watersheds as a result of early snowmelt and increasing evapotranspiration. Spatial and temporal variability of stream flow and nutrient loads under the transient climate scenario indicates that different approaches for future water resource management may be useful( Chang et al. 2001. j.Am.Water. REs. Asso. ). 

In a forest ecosystem, climate change was predicted to have a positive impact by increasing the future supply of base cations from weathering,  thus compensating their removal by biomass harvesting. However, additional inputs of nitrogen and potassium will be required to ensure sustained forest growth under intensive biomass harvesting( Aberne et al.2102. Biogeochemistry 107: 471-488).

Climate (especially precipitation and temperature) and vegetation have long been known to have significant effects on pedogenesis and macronutrient cycling in soil . Isolating each of the individual soil forming factors (which include climate, vegetation, parent material, topography, and time) is challenging as many factors often co-vary . For instance, assessing the effect of climate on biogeochemical cycling is challenging as often vegetation varies with climate as well.

Some thoughts please....

Thanks Pierlorenzo , looking forward to your excellent feedback as usual.  

Abhishek , let me send  my heartfelt compliments for such a wonderful set of quarries , where we need to tease our brains  to find the plausible answers of these.  Its not so easy to find convincing answers . But , let me try out some of them ;

If there is distinctive change in climate in terms of carbon dioxide along with temperature  ,  different  soil microbial communities are first to undergo reorientation  in their structural composition ,besides metabolic  chnages , as a mark of their extreme sensitivity . These microbial communities are infact the genuine bio-sensors to let to warn about the possible fluctuations in existing climate . And , this should be our ultimate objective , if a land use is sustainable with certain  plant -microbiome , how can we continue to run with the same microbiome even under changing climate ?. How can we develop that necessary  microbiome resilience in a highly productive land uses ..?

I deliberately avoided going through the supra comments except for a cursory glance with an object not to affect my thought process. Simple principle is we become what we eat. Similarly, the crops quality depends on the quality of food and shelter we provide. In this context, soil microbes and macrobes serve as benefactors and contributors to crop growth and development, practicing the concept of symbiosis in letter and spirit. In a nutshell, let us make the soil as the best source of food and shelter for soil biota without the latter as the scavengers meant to tolerate and absorb pollutants. 

Well said Dr Reddy , no doubt improvement in soil organic matter through better build up of microbial population will play the pivotal role to moderate the climate change related issues . How effectively , the changes in soil microbial communities sense the changes in either soil as an environment or  in atmosphere loaded with higher carbon dioxide plus temperature as biological sensor...?

Thanks Dr Singh  for your appreciation s...

 Discussion has become very interesting, but how shall we address the changing dynamics of nutrients in relation to climate change?

Dr Malhotra , thats the point , the centre stage of  whole discussion . Some of the responses from Dr Kundu , Abhishek , and me addressed your genuine concern. 

Terrestrial plants were experiencing a global imbalance of essential elementswith carbon assimilation under CO2 enrichment. This may intensify the existing stress of micronutrient malnutrition of human in the future. Very few studies have investigated the feffect of CO2 enrichment, warming, and their interaction on soil micronutrient availability and plant uptake in cropland under field condition. So appreciative of you Abhishek.  Dr Kundu also referred the same work...

How  does micronutrients availability as apart of soil fertility  and plant nutrition coordinate together  in response elevated CO2 and temperature ...?

I think redox mediated nutrients like iron and manganese will be most affected by climate change related issues. However, with aridity developing through climate change will turn iron and manganese more difficult available. 

I agree with you Dr Shirgure. Climate change will increase the aridity index and nutrients like nitrogen iron will be most transformed into lesser availability.

Good  point by both of ypu Dr Shirgure and Dr Deka , soil salinity is anticipated to be on upsurge with current trends of climate change , so we need to develop our preparedness to fight with drought /aridity and  salinity ,, and accordingly the mitigation/adoptation strategies..?  And nutrients like N, Fe, Mn, S, Zn are going to most affected . Dr Kundu highlighted these issues earlier very nicely..

Yes Abhishek, it is true such information are lacking. But the question before us is still unanswered that how climate change will affect the availability of nutrients to plants.

Yes , i agree with both of you Abhishek and Dr Malhotra. Unfortunately , very little is attempted with regard to micronutrients , with an exception of nutrients like N, P,  and to some  extent K.  As i said earlier also , Dr Kundu touched upon this issue...

Yes, we need to strengthen research work on micro nutrients in different conditions. 

Abhishek , let me appreciate your constant efforts appraise all of us with many developments on the issue , we are debating over so many days . the concepts practiced as such i liked all of them , but results seem to be bit undone. An experimental soil whose initial organic matter content is 3,32% , indicates soil is of initially good fertility , and , therefore , would not be in a position to satisfy its carbon need (means weaker sink for carbon loading ) vis-a-vis  changes in other  soil properties..?

How would you differentiate these practices as a part of climate smart agriculture as opposed to normal practices for moderating the usual effects of climate related changes..?