What a series of questions!  May I suggest that that nutreint balance is best assessed by plant analysis, and that the soil condition should be monitored to avoid acidification, especially at depth, where it is difficult to remediate.

Dr  Srivastava, best use of soil resource can be made to develop multiple cropping sequence provided you have specific requirements in terms of soil and climate. Spatial variogram will be more useful .

Can any body throw some light on good amount of work done in National Bureau of Soil Survey and Land Use Planning, Nagpur on soil suitability to different crops and also the production potential of different soil series?

Dear Dr. Anoop,

Thank you for your very comprehensive questions.

For soil fertility constraints a detailed, a high-resolution fertility analysis and functional soil fertility map consisting of nutrient status and balance is instrumental for improved fertilizer recommendation and agricultural policy reforms. This can be created through comprehensive soil sampling and analysis. Soil fertility maps will aid with the creation of new fertilizer blends for a certain soil and crop type.

Nutrient balance (nutritional information) will be used to create optimal fertilizer balances and inform application rates for different crops. I think these are important considerations: 1) Identify soil fertility deficiency and develop preliminary fertilizer recommendation; 2) develop critical value for economically optimum nutrient combination; 3) validate fertilizer recommendation containing both major and minor nutrients generated by soil information development efforts; 4) test and calibrate nutrient requirements of the intended crops based on soil nutrient content of specific areas; and 5) develop recommendation and extrapolate result to wider set of farming systems.

Cropping system practices are the major factor directly affecting the productivity and quality of crops. Sequential cropping is among different cropping systems. In order to plan a feasible and profitable cropping system, identification of the different crops and farming systems are very important, e.g., cereal based, perennial crops based, mixed farming, etc. Cropping sequence and land utilization efficiency can be inter-related directly or indirectly. Soil resource inventory can assist in selecting the types of crops that grown on different soil types and fertility classes.

Paul : I agree with you to take best advantage of plant analysis  to identify nutrient constraint  and soil analysis to monitor the soil conditions . But , our  whole attempt is jeopardized by the absence of such comprehensive information on soil-plant diagnostics .

Barbara : Nice attempt .I would appreciate , if you can further elaborate , very interesting .

Sikha: This is what I have raised , how to go about . there is no doubt about the utility of soil fertility variogram , but look at the technality and amount of time plus expertise available to develop such  maps to be later used as decision support .

Dr Rao : Its long time you participated in the  discussion .

Getachew :There is absolutely no doubt about the utility  of soil resource inventory . There have  further been advancements  in terms of incorporating the length of growing period, potential evapotranspiration etc . NBSS and  LUP have done pioneering work in this regard. we are hoping someone to interact on these issues , it will be a good discussion on  such an effective platform.

I suggest to use the 4th revised soil fertility classification which can be usefull to distinguish best major land uses types.

Sanchez P.A., Palm C.A.and Buol S.W., 2003, "Fertility capability soil classification: a tool to help assess soil quality in the tropics", Geoderma, 114, 157–185.

Dr. Srivastava my further querries are: what parameters of different crops do you consider to optimum, especially when a sequence of crops are involved; do you have some decision support; how exactly a set of soil properties are really accountable to a given cropping sequence 

Dr Deka thanks for your response. Exploiting soil resource for a crop or a sequence of crops in a given area involves a large number of decisions at various levels. Yes , there have been various models used to decide the crop sequence . Dynamic process based simulation models appear better suited to predict changes in land use intensity than empirical , stoichastic or static optimisation models. Decision on crooping sequence is a kind of decision making through a range of response options. Various models  for land use have been evaluated in a study ( Lambin et al. 2013, are agricultural land use  models able to predict changes in land use intensity ,Agriculture,Ecosystem and Environment 82:321-331). As I said earlier also , soil site- crop response studies will further   throw some useful information on optimum requirements of soil properties as well as climate in a given agro-ecological region . A concept of agr-oecological zoning ( By stewardship NBSS and LUP)has been implemented covering entire range of soils at various taxonomic levels . Such studies have really given strong impetus to prepare a blue print of the crops to be grown depending upon the soil properties. Enclosed PDF will further give you some useful information as a case study.

This question is complex. but I think that whatever sequence adopted for instance legume-cereal sequence, there is no way the soil nutrient will not be imbalance. Consequently, monitoring the performance of the succeeding crop at the early stay of development is one major way to make decision since the plant performance is the best indicator of the quantity of the soil resources in any given area. 

I agree with you Sunday , but the we are so heavily constrained by the absence of such  monitoring criteria , whether early stage of cropping or later  years of cropping , though after few years of cropping , you will automatically come to know abut the sustainability of that cropping sequence in space  as well as time.

Dr. Anop Kumar! your questions were of practical nature and very important for many stake holders; researchers, land use planners, soil surveyors, farmers and government agencies. Some very good answers were presented, especially by Dr. Getachew Agegnehu. At this stage, many of the countries have already completed Soil Survey and Land Evaluation. The Land Suitability surveys classify mapping units into S1, S2, S3 and N1 and N2. The crop requirements in terms of soil, climate, slope and water are also enlisted in such classification system. These can be very useful to decide the cropping systems for an area. As recommended, detailed fertility maps can help in deciding the nutrient requirements.    

Thank you Dr Nazir  for so nice elaboration  .  Let us take an example of an area , you are really not conversant about either soil  types or popular/conventional  cropping pattern You have developed  soil resource map on hand  and based on this map , you have roughly the crops options or main cropping sequence plus one or two options of compatible cropping sequence. Here from , let us know , how to go about ?. My second querry is S1,S2,S3, N1 and N2 , how far they are effective in field when evaluated in terms of performance and such classes have to be in tandem with specific crop?. What is your further response ?

The soil and water + climate of the area itself can tell a lot about selection of crops and cropping systems. For example, if you have good soils free from salinity and sodicity + good quality water supplies then you have broad choices of crops matching to the climatic conditions of that area and the soil texture, structure, drainage and nutrient supplying capacity of soils. If you consult  'FAO (Food and Agriculture Organization of the United Nations) (1985). Guidelines; Land Evaluation for Irrigated Agriculture, FAO Soil Bulletin 55, Rome ' you will find requirements' criteria for different LUTs (land utilization Types) for different parameters of soil, water and climate. Matching with these criteria you can select best crop, cropping system or land utilization for the area. The concepts of S1(highly suitable), S2 (Suitable) and S3 (marginally suitable)  as well N1 (temporarily unsuitable) and N2 (permanently unsuitable) work very well if you have enough information on soil, water and climate. 

Thanks Dr Nazir once again . This parametric approach is very tedious , especially when you assign various scoring for a given parameter , there is very thin line from S1 to S2 to S3 , and when you base this approach on soil-site crop response relationship. Our further querry is , how do you introduce a change in cropping sequence , is it the same parametric approach of soil site evaluation undergoing frequent evaluation and concurrent refinements ?

I invite my friends to kindly share your experiences on different kind of soil site-crop response relationship . this will pave the way for developing better soil-crop optimum requirements   since soil resource inventory involves varied decisions at various levels of soil site evaluation .  

Let us listen from colleagues what to do with degraded soils. How cropping sequence is decided on degraded soils

Interesting discussion on important topic.Though it is desired to match profile characteristics,fertility status and water availability  in soil etc with crop/cropping system requirements,in practice it is not happening.Cropping system is decided by the farmer and we are providing the nutrient and water recommendations.Societal needs, government policies,irrigation, crop yield levels and attractive prices will decide the cropping system in any area.Some examples are over 10 million ha of rice- wheat system in Indo-Gangetic alluvial soils ,Soybean-wheat/gram system(over 4 million ha )in Madhya Pradesh( in central India) and spreading of soybean, maize,cotton  and gram(chickpea) to several states in considerable area.In all the cases traditional pulses and millets were replaced by high yielding and high price fetching crops. Now vegetable crops are entering into several cropping systems. Most of the studies conducted by the scientists in some districts were after the introduction of a particular crop/cropping system.Also different proportions /percentages of land area of a particular  crop are under S1,S2,and S3 categories of FAO. So, we can do midterm correction but we may not be able to lead the farmers by advising suitable crop/cropping system based on our soil resource study.Now we have GIS and GPS technologies to map the soil resources.With appropriate resource allocation,  soil quality and productive rating of soils for dominant crops in a district can be made and mapped for use by the govt.,extension personnel,NGOs and progressive farmers.

Thank you Dr. Subba Rao, You have mentioned some practical analyses that are deriving the farmers what to grow. Of course price is the deriving force above all. It is very difficult to teach the farmers and refrain them from immediate profits, though these may not be sustainable in the long run based upon land evaluation studies.

Dr. Rao do you feel these changes in cropping pattern are governed by whether by introduction of soil resource like concept or farmers own choice? 

Dr.Deka, I have already mentioned the factors responsible for the farmers choice to grow a particular crop.A high- yielding rice  crop with better support price may be better choice than a short duration pulse crop  in Indo-Gangetic plains.With attractive price and good yield potential soybean is a better crop than sorghum in M.P.Compared to residual pulse crop like green  gram or black gram,very high- yielding maize  hybrid may be a better alternative for  farmers in Guntur district in A.P state.Government  crop missions,incentives in the form  of seed kits distribution,fertilizer subsidy etc all contribute to change of crop/cropping system.However Government can seek the soil based information from institutes like NBSS&LUP,Nagpur for promoting a particular crop like an oilseed or a pulse crop in a particular area.

Friends based on the  earlier remarks, how can we make soil resouce -based information more accountable towardsr precision-based crop advisory than the incentives of short return, though there there is no doubt , the raising of  crops in a given piece of land or an area is more governed by the profitability and maket value.

We are perhaps drifting from main course of the topic. Please cite such success stories where soil resource inventory has been effectively used in harvesting potential productivity. The answer such as this takes away the incentives of soil as a natural resource. Dr Rao my response is addressed to you please.

 Dr.Deka,I appreciate your point of you.In my first response I requested the colleagues who have worked in this field quite a long time to respond.We did not get response from scientists who have really worked in this field.Otherwise we will not be able to get right answer and real problem on ground level .In eighties there was a lot interest in utilizing  well defined soil information in maintaining soil fertility and crop productivity.With respect to potassium  myself and my colleagues  tried to  use soil series as the basis for characterizing  fertility status ,provide soil test based recommendations and also monitor soil fertility over time. Potash Research Institute of India,Gurgaon, where I worked , characterized  30 soil series for soil properties  including mineralogy,fertility status,critical limits and recommendations for K responsive soils and also monitored K fertility status over time. But such soil information based studies did not progress well for other nutrients.Some colleagues from NBSS&LUP studied the production potential of crops on some well defined  soil series in different parts of the country.Probably they related crop response to soil properties and nutrient status. If such information is compiled  for different production zones and passed on to developmental agencies  ,they will understand ,appreciate and use the information in farmers fields.I do not know how much is done or happened in this line.

Thanks Dr. Rao. With these responses, don't you feel Dr. Rao,  we still have a long way to go before soil resource maps are effectively put to use for meaningful crop planting

Dr.Daka,generating and collating information at soil series level and use it in crop planning and input use is  a difficult task.I know that some states like Punjab ,Haryana and Tamilnadu have  very good soil information up to soil series level.In the soil series reports information may be available on current crops grown and suggested crops based on soil information(soil properties and fertility status.).I do not know how far this information is used in crop planning and input use.Also as the information becomes old one has to revisit and update the information to make it relevant to current needs of farmers.

In one of my earlier responses I have referred to district level studies on land suitability for a crop or different crops, matching the land characteristics with the crop requirements,like FAO publications referred in the discussions.I could locate a publication containing soil-site suitability for major crops in India.Manual soil-site suitability criteria for major crops .LGK Naidu and other s.Krishikosh.egranth.ac.in/bitstream/1/2034266/1/NBSS-28.pdf

Extending the nice   discussion further , we have evaluated the soil cite characteristics in response to behaviour of citrus and fixing the optimum level of  both soluble and exchangeable phase of the soil at various depths as part of massive effort on developing soil suitability guidelines for citrus . Such studies have aided in expanding citrus in newer areas avoiding soil related constraints , besides their effective nutrient and water management . Enclosed PDFs will throw some useful information .

Designing a Cropping system is a very complicated task that involves not only the soil fertility, texture, organic matter, topography, etc but also the whole physical, biotic, climatic and social environment in the target area. Cropping systems research works were done by IRRI in different sites and multidisciplinary scientists were involved. I would like to suggest a reference book to you by Zandstra HG, Price EC, Litsinger JA and Morris RA. The link is listed below and if it does not work, try to search in the internet the handbook "A methodology for on-farm Cropping Systems Research". This is available free online.

Thanks.

https://books.google.com.ph/books?hl=en&lr=&id=f9RBs8VE8dsC&oi=fnd&pg=PP2&dq=cropping+systems+research+methodology&ots=IF_xFt81dM&sig=uin4J8r_vz3NhgnrtccE2r466Pw#v=onepage&q=cropping%20systems%20research%20methodology&f=false

Thanks Dr. Rao for update. But such publications have limited utility when you consider huge variation in soil properties and the related guiding factors to develop a scientifically sound crop planning on a commercial scale.

 Dr.Deka I appreciate your interest in the subject .Your interest encouraged me to go through the publication last night.For some crops there is sufficient background data to  fix the soil suitability  criteria to rate the site  into S1,S2,S3 etc categories.  For some other crops the data is inadequate.But still I appreciate the efforts of the authors  to develop criteria for all major crops.The second part is to utilize the suitability criteria for production of a crop / some crops  in  different districts of the country and rate their suitability.In a country like India to do this job or work for around 600 districts is Himalayan task.The third and most difficult task is whether we encourage or discourage farmers to grow a particular crop.Whether for the sake  of maintaining or safe guarding soil quality  or environmental protection will  the farmers discontinue a particular crop or they go for a recommended crop if it is not remunerative for them.Ultimately who will enforce change and how?

Interesting, My simple concern is why don't we implement soil based cropping sequence. Why farmers have to decide a crop simply for the sake of only profitability without bothering about soil health and environmental health which I feel is perhaps  more important.  Will such practice be allowed in other technologically advanced countries where natural resource play so pivotal role. If soil quality is lost because of wrong crop selection then where is the long term sustainability of cropping sequence. How can you see sustainability by separating the soil and associated environment. 

Dr Deka , we  do implement soil-based  crop planning , however the intensity of adoption of such strategy may not be that much encouraging . While suggesting the sequence of crops to be grown , we do take care of  potential  nutrient mining  from soil , but hardly address the issue relating the long term   impact on environment  . We awake only when  such practices start displaying the immediate adverse effect either on sustainability in  spatial and temporal productivity or crops are no longer remunerative to be raised . I hope Dr Rao  will agree . But Dr Deka , your points are very pertinent , we can not look  about a remunerative crop sequence without looking into long term impact on soil health  and environment  . now-a-days , we have started looking towards earning carbon credits through benign crop sequence in a farming system mode .

I see that this important discussion is taking impetus and becoming highly interesting. It is very clear that Suitability classification is taking care of all relevant soil qualities and aim at sustainable land utilization as well as taking care of environment because it is an important consideration in the deciding criteria. Dr. Deka is right to insist in this regard. However, Dr. Suba Rao is pointing out the social systems, adopted cropping systems by the farmers and allied difficulties in this regard. Dr. Anoop Kumar pointed out the final outcomes of the second track. Yes, these are to happen finally if we go against natural potential of land and water resources coupled with climate and very important consideration of the environment. It is our moral duty to handover these resources in a good form to the new generations. As scientists we should do our best to teach the farming community what is the best for them, the nation, the country and the globe. 

Thanks Dr Nazir  for such an outright emotional response , but truly logical in  implementation and consequences. Yes  Dr Nazir , you  are dead right , we need to educate our  farming community to keep an vigilant eye on the annual changes in soil properties that undergo with every crop harvested from their field . An equally vigilant eye is also needed now with so much growing concerns about the environment , it could be even underground water quality . But Dr Nazir as a student  of soil , how do feel , is it not so alarming that there is least intervention of the soil-based information in shaping up the cropping sequence in a given farming system mode. Dr Rao  has rightly highlighted , farmers have their own choice of crops , irrespective of what your soil recommends.  And Dr Deka has really rejuvenated the whole discussion .

Dear colleagues,I have come across changes in  crop/cropping system  because of pest problems and associated high costs and debts forcing the farmers to change the crop.Even recurring droughts also similarly forced  change in crop/cropping system(at least temporarily or partially).Example  is  cotton in some parts of the country.Even though the soil and water related problems have been  highlighted as in rice-wheat system in Indo-Gangetic alluvial soils,no change in cropping system occurred .Of course we have been highlighting the efficient use of irrigation water ,conservation agriculture,balanced  and integrated nutrient supply etc.

Yes, no one can negate the facts stated by Dr. Anoop and Dr. Rao. Even some temporary factors can change the cropping systems of an area, may be even for a limited time. Dr. Rao gave example of Rice-wheat cropping system in Indo-Pak alluvial soils. Yes, besides other factors, the eating habits of people force them to sustain  this cropping system though it is not so much economical because they want to eat their own rice and wheat while cash crops like cotton are easy to change.

Friends,  when we talk having carbon credits through cropping sequence, do we have data on carbon sequestration ability of different cereal crops and pulses

Dr Deka days are not far off , when you have to consider the carbon budget of the whole cropping sequence in a   farming system .  Off course soil is considered to be a  better sink for atmospheric carbon to be sequestered. I request my learned colleagues to share their experiences on this very important issue, since our  current state of knowledge on this issue  in  Asian context is still in a developing stage. Let me share some very useful information about perennial crop like citrus , as to what an extent , such perennial crops could serve the environmental sustainability , besides income generating and livelihood earning cash crop . In Spain , in 12-year-old Valencia orange trees , it was estimated that trees can fix 50 kg C per tree per year, out of which fruits and new flush  leaves  accounted for more than 75%, and only rest of the  25% were sequestered by old branches , trunk and tap root. Leaves fixed total C of 15.4 Mg C per ha per year , with loss of C through respiration of about 2.7 Mg per  ha per year, thus  establishing net surplus of 12.7 Mg C per ha per year. I am enclosing the relevant PDF for your reference please .

 We have not answered the question of Dr.Deka regarding carbon credits for cropping systems.Carbon credits or incentives are given to carbon set aside in soil or vegetation for long time,not using for other purposes.We use the term carbon sequestration for long term storage of carbon in oceans,geological formations ,vegetation and soils.If afforestation is carried out on degraded or waste lands and the forest is not disturbed  we can claim carbon credits . Converting agricultural lands to agro- forestry may also get carbon credits..Even if permanent grass land  is established on degraded land we may  get carbon credit but grazing should be rotational /not disturbed.In agricultural soils where we cultivate annual crops with conventional  cultivation we may not get any carbon credit.Conservation agriculture  with zero tillage or minimum tillage may get carbon credits provided we continue this practice for long time with out disturbing the system. In India, in true sense, we have no authentic area under  conservation agriculture. Under my convenorship National Academy of Agricultural Science,New Delhi arranged a brainstorming and published a policy paper on Carbon Economy in Indian Agriculture Policy paper no. 69.This can be consulted on www.naasindia.org

Dr Srivastava , it is so heartening to see that you have added another dimension to whole discussion . How a sustainable cropping sequence serves in maintaining the ecology of either soil or climate , both are important . Our friends must interact on this issue.

Sir (Dr Rao), you have added some information about conservation agriculture and afforestation . We want to know about the carbon sequestration under different land use system . If you have any information , please share it .

Dear Dr.Singh,Please refer to the following authoritative article published from Rothamsted  Reseach,U.K. Soil carbon sequestration to mitigate climate change: a critical re-examination to identify the true and the false. Powlson,D.S.,Whitemore,A.P. and Goulding,K.W.T.European journal of Soil Science,February,2011,62,42-55.This paper can be downloaded.The references mentioned in the paper can also be consulted.

Dear colleagues ,after all the discussion, are we not missing the major concerns emerged from the discussion?We have in India the soil  suitability criteria for major crops including horticulture and plantation crops.Also the suitability assessments for  dominant crops in selected districts  are available.From this where to go?Based on the scientific information will the state governments implement the changes in crop/ cropping system?By seeking government support and using the techniques of remote sensing and GIS can one  advice for covering as many important districts as possible?Based on the information can scientists  develop maps for  dominant cropping systems in different agroclimatic/ecozones to guide the governments in state and centre to plan for sustainable agriculture and soil health.

Let  me share  with my learned colleagues on this important  point raised earlier . We still have a long way to go before we have precision -based assessment of site evaluation and crop-based assessment of nutrient constraints. We in India ,  do not think ,  we have the soil fertility criteria with respect to horticultural crops including tuber , plantation, spices and vegetable crops, off course with certain exceptions for the crops like potato , banana, citrus , mango , grapes, rubber , tea, coffee etc... We do have digitized soil fertility maps for many districts ( some 160  odd districts or..) , which is being now used as a part of the second phase by superimposing the specific  crop boundary  to have a first hand information  about the nutrient constraint assessment . This will gave the generalized information , not more than that . In this regard , very shortly geo-portals are in the pipeline to be flagged off very soon .

There are hardly any literature about the threshold limits of either soil or plant part analysis basis .Especially horticultural crops , grown under such different agroclimatic conditions . Take an example of tea alone , don't go far away . Application of GIS remote sensing , ok, but only a rough  evaluation , I can say .

Dr.Deka Please go through available scientific  literature and make any comments.Have gone through the publication brought out by NBSS&LUP with Naidu as lead author,Manual soil-site suitability for major crops  in India?Could you go through any of the soil suitability  studies for  crops in any districts of India.Have you seen any map produced for any crop from one the Divisions of IARI using   remote sensing and GIS tools.At least I  never made enthusiastic comments with out any basis and sufficient back up information.

My  learned colleagues , can you share the experiences of your own country , what kind of procedural steps are effectively followed to utilize the soil resource information for deciding the cropping sequence . If you have crop specific soil property limits in any form , can you please share , so that we are benefitted . I am not talking of what farmers do . What should be scientifically done to exploit  merits of soil   as a natural resource .

For the information of the followers of this  question, I furnish  here under a publication providing  critical limits for major nutrients and micronutrients  in soil for several crops and critical limits in plant for several crops.But  the book may not provide information on any crop of your choice.Methods of Analysis of soils,plants,waters,fertilisers & organic manures.Edited By HLS Tandon  Fertiliser Development and Consultation Organisation 204-204A,Bhanot Corner,1-2Pamposh Enclave New Delhi-110048 India email for contacting :  [email protected] or [email protected]

Dr Srivastava , nowdays , we look soil resource as comprehensive resource alongwith ground water . introduction of agroecological zoning to include the growing period has eased out the land use planning . but , frankly speaking , we are far from reality . We are yet to develop acomprehensive system where soil resource is used as an effective tool of crop planning . Hope my other colleagues endorse the concept .

Dear Dr.Singh ,there is no limit for new developments in any subject but we have to build over or add strength to already existing knowledge base.Even with existing knowledge ,excellent work is being done from remote  North East part of India.We have to look .around and see what others are doing.I am providing reference to one good piece of work from Meghalaya. Land suitability analysis for orange&pineapple:a multi criteria decision making approach using Geo Spatial Technoly .Das,P.T. and Sudhakar,S.Journal of Geographic Information System,2014,6,40-44.Open access Journal.There are three more papers from North East apart from other references(16).

To the take the discussion further , let me introduce the concept like nutrient budgeting on Alfisols. We also need to address this issue in the ambit of whole crop sequence in a given agroecological region or sub-regions per se . I am enclosing my PDF highlighting the process of computing the nutrient budget using coconut-based pachauli cropping system . hope , you will like it to respond.

Please find enclosed some interesting work...