In reference to your first question I would suggest that depending on your Bio Region

There may be a shortage of appropriately mineralized biomass for your soil requirements. Biomass can not supply minerals not in supply in the soil it comes from. For instance in Western Canada there are dramatic shortages of phosphorus in the soil. High concentration organic source material with complimentary mineral balances is how I make soil adjustments for optimum growth and nutrient values. This does not currently work with all local biomass sources. I bring in seed meals, from oilpressing,usually an animal feed, as a bulk npk correction. It is High in phophorus and low in pottasium, that we have far too much of in our soils. This works hear because seed meal is shipped in bulk train cars from the canadian praries and can be had at relatively low cost. If This was Not available I would probably use concentrated rock phosphorus with local biomass for humus and nitrogen. This would be the most reasonable alternative for phosphorus deficiency in my opinion as all most no other reasonable sources are available and unrefined rock phosphorus is far too High in both lead and cadmium to be healthy. Phosphorus deficiency is common in many parts of the world. I would refer you to a free online library of excellent resources at soilsandhealth.org in reference to your other questions for in depth answers.

Regarding your second question you could consult the following papers:

1.) Seufert, V. et al. Comparing the yields of organic and conventional agriculture. Nature 485, 229–232 (2012)

2.) Badgley, C. et al. Organic agriculture and the global food supply. Renew. Agr. Food Syst. 22, 86–108 (2007)

To put it in a nutshell: yield differences are highly contextual, depending on system and site characteristics. You can find examples of high differences (>40% lower organic yields), examples of nearly equal yields, and some sources even report yield gains under organic agriculture compared to conventional. However, not all of these studies are uncontroversial.

Regarding the first problem I would propose to use the unconventional sources of nutrients which includes not only the organics but some naturally occurring rocks and minerals. These rocks and minerals contain significant amount of plant nutrient but as such not fully available to plant . Some modification (physical/chemical/biological)is required to make the nutrient available to plant. For example phosphocompost is made by enrich ordinary compost with rock phosphate during composting process which is an excellent source of phosphorus

In regard to your first question there is lot of locally available and farm generated organic resources are available. If these available resources are effectively utilized they contribute more towards organic inputs

Regarding second question, yield level in organic system may goes down in initial years. If, organic system is followed continuously defnitely it will increase the yield. Once organic carbon content is build up in soil by organic farming and increased nutrient supply continuously will increase the yield.

Regarding third question plants can't differentiate the nutrient sources but it is the matter of pollution of the environment and fertility status of the soil. If we go on depending on inorganic sources of nutrients it will pollute the environment and reduces the inherent productive capacity of the soil in turn leads to decrease in yield levels over a period.

For your 2nd question.

if you change to use organic fertilizer from inorganic, there must be inadequate nutrient supply to plant/root, immobilization process also contribute decreasing yield.

I never use just straight organic matter/fertilizer to supply nutrient in my farm/field.

it take much time for bacteria-fungi-etc to decompose-mineralize nutrient from organic pool.

Organic matter, i believe, not the main source of nutrient supply. Using organic matter as soil conditioner (both physical-chemical-biological aspect).

cmiiw.

In reference to your 2nd point, I indeed agree that yield goes down if you rely on organic farming on large scale. With respect to the weed problems that emerge in large scale organic farming, one can imagine that large scale organic farming is not realistic.

I totally agree with all the 3 arguments. However, the only factor these 3 points do not take into account is impact on environment. That is certainly a growing concern all over the world. So, I would say judicious and efficient use of both organic and inorganic is the way forward and the proportion of both depends on the local conditions dictated by availability of organic resources, compeiting demands for organic sources, soil fertility and crops grown.

But, what about environmental implications? Organic farming may lead to a more "natural" cropping system. However, environmental risk associated to incorrect management may be taking into account. For instance, inadequate rates of organic fertilizers can pollute aquifers and may favor the presence of pests. So it is strongly important to consider how the application of organic materials is and the property of these. Moreover, not only fertility and yield is important, environmental consequences are too.

From experiment e the challenge has to do with the first... Insufficient resources at least in dry Savannah agro ecologies. Natural bushfires long dry seasons catalysts the rate of om losses.

One point being missed is weed management. In my part of the world organic systems have difficulty dealing with weeds. Either they must cultivate frequently and thus induce soil carbon loss and loss of soil quality, or tolerate higher levels of weeds, which poses serious issues for other farms and surrounding environment. In my opinion organic systems are best suited to tropical systems with high carbon turnover and mineralisation and regions with cheap labour for weeding.

There is an abundance of organic material available for agricultural input, but just adding raw organics to soil is not particularly helpful in the short-term. Better to compost the organics first, then add to cropland. Then following yields do not diminish, waiting for the microbial populations to perform nutrient cycling.

Both nutrient cycling and disease control by natural means are totally relative to the volume of the full ACTIVE (not dormant) BENEFICIAL microbial soil community available. Increase the soil volume of the full microbial community - quick and easy to accomplish on-site, in liquid form, dispensed via existing farm equipment.

Both mulching and cover cropping should be considered in weed control.

Agree withs arguments no 1 &3 disagre with no 2

That sufficient organic inputs are not available is a misnomer. One can truly state sufficient organic inputs are not MADE available to organic farming due to human failure in preference to synthetic chemical inputs which are subsidized and rule the markets.

Yield levels steadily and linearly increase with time with organic inputs eliminating crop failures as these inputs are eco-friendly and environmentally safe.

All organic inputs undergo mineralization process due to which inorganic nutrients are released slowly and steadily to meet the crop nutrition needs corresponding to their absorption by crops in different stages of their growth and development. Whereas, in case of inorganic inputs, the nutrients are released in very high concentrations much beyond the ability of absorption and needs of crops. It is true that plants can not differentiate between organic and inorganic inputs. But, it should be remembered always that organic inputs provide food for soil sheltered micro and macro flora and fauna which are indispensable to the holistic development of crops both in quality and quantity. Organic inputs thus serve as food for soil biota whereas inorganic inputs destroy the soil biota besides causing pollution of natural resources such as soil, water and air which in turn spoil the quality of crops, animals and finally humans.

Great thread. Here are my thoughts on the three points:

1. not sufficient organic inputs are available

This, I think, is the most difficult of the three questions. I think Kunuthur captures the essence of what I would say, which is that nutrients exist in a cycle. Both the size and rate of that cycle can be manipulated over time. The cycle in agriculture has losses from 1) leeching of nutrients our of the system and 2) removal of nutrients from crop harvest. In the conventional argument people focus on the second aspect, and argue that low-input farming methods cannot cope with the losses of nutrients due to crop harvest. Organic farming methods tend to do a lot to increase the total size of the nutrient cycle and enhance the total potential fertility of a soil, which is an undeniably good thing. As Kunuthur points out these will take time to create realized effects in the soils. But allowing for localized inputs, particularly from very high nutrient loads such as waste water, natural erosion, areas of high nutrient uplift (from deep rooted plants), etc. I would argue that organic methods can supply the needed nutrients for global level food production needed to feed 10 billion people. I don't think we could do it yet, due to lack of investment and infrastructure, which leads into the next point.

2. yield level goes down with organic systems or is not comparable to chemical farming

No...total disagree. Indigenous agro-forestry systems in several areas around the world have shown yields of 15 tons/ha, more than conventional corn, wheat, or soy yields in industrial farming. Furthermore, the efforts in plant breeding in particular over the last 200 years have been focused on industrial type, mono-cropped systems. The very, very few plant breeding facilities that are focusing on organic systems have shown huge gains in yield when breeding plants for organic systems. So growing plants bred for industrial type agriculture in organic systems and then saying they don't perform as well is a rigged game, and of course they are going to do worse. Just like if we bred plant for an organic system and grew them in a fertilizer heavy system they would perform worse...in fact could possibly die due to being "burnt" from high fertilizer exposure. You can't compare the current state of the two system when one system has received over 99% of the agricultural funding over the last 200 years, and even with that case there are again agro-forestry systems that still show comparable and in rare cases higher yields.

3. Plants can't differentiate between the sources of nutrients i.e organic or inorganic.

I hate this question. As a soil biogeochemist I have to say that yes, plants can't differentiate between the two. It's just like an artificial vs. a natural flavoring (which only differ in the source from which the are distilled)....if you give two vials to a chemist he cannot tell which is which. Chemically the individual molecules perform exactly the same. But my problem with this very reductionist argument is that as a whole I would say that the soil can tell because an inorganic source of nutrients in not going to come with the suite of other elements and constituents that an organic source comes with. If you just pour on nitrogen without, for instance, all the carbon that comes with organic sources that is greatly going to change the microbial community, the balance of nitrogen to everything else in the soil, and therefore the entire nutrient cycle. So while chemically I aatgree plants cant tell the difference, I think they can tell of the imbalance of the source (which can happen with organic sources too).

Let me conclude as sufficient argue and information has been given by the LEARNED participants from that, it can be concluded that

1. Sufficient organic inputs are available the need is their integrated and efficient use.

I would like add my experience of arid zone( Rainfall below 500mm)-Availability at farm level was influenced by several factors like rainfall, cropping pattern, size of holding, availability of labor etc. In general most of the places farmers used raw cow dung, kept under sunlight for months and this caused great loss in nutrient availability ,mainly that of the nitrogen. On an average 1.5-4.5 t/ha organic manure was available at farm level in the form of crop residues and animal dung.

-Availability increased at village level by 1.5-2.0 folds mainly because of some farmers kept animals for dairy purpose. Also there are unproductive and old animals available at village level in large numbers. These animals may not give milk but provide manure in substantial quantity. Cattle provided 4.6 to 11 kg/ha/yr ( total agriculture land/total number of animals in the village).Trees are the integral part of farming system of arid zone and contribute equivalent to 0.04t manure/tree. Trees available in common land ,protected areas, waste land etc. also contribute to organic input availability at village level Availability further increased at district level as intensive dairy farming was observed in peri-urban areas. After addition of organic input availability from all the sources the figure reached to 4.5-5.0 t/ha. This amount of organic input is sufficient for rainfed farming in low rainfall areas. The availability of nutrient can be further increase by adopting following management practices-

1. Crop rotation with leguminous crops like cluster bean, moth bean moong bean etc.

2. Avoiding heaping of dung under sun and use of improved methods of composting. In arid zone due to shortage of water and high temperature pit composting method has been found most suitable.

3. Tree leaf litter, animal urine, bones of dead animals, non palatable weed biomass are some of the other rich and underutilized sources of nutrients that can suffice the nutrient requirements of the arid zone production system.

Therefore, organic inputs are available in sufficient quantity in low rainfall areas the only need is their efficient utilization.

IF THIS MUCH IS POSSIBILITY IN ARID ZONE THAN CERTAINLY THE SITUATION WILL BE MUCH MORE BETTER IN HIGHER RAINFALL AREAS.

______________________________________________

2.Yield response depends mainly on two conditions A. Drylands where chemicals have been used in limited quantity and soil biological system is not disturbed, with the integrated application of all eco-technologies the yield start upward growth from the very first year

B. In irrigated areas where heavy chemical are used that disturbed micor- ecosystem of farm/field that need 2-4 years to restore and then either comparable or higher yield than chemical farming is possible and people reported.

THEREFORE NO YIELD LOSS BUT IN ADDITION TO SUSTAINABLE YIELD , ORGANIC FARMING REDUCES COST OF PRODUCTION, HELP IN CLEANER ENVIRONMENT , GENERATE EMPLOYMENT, HEALTHIER PRODUCER AND CONSUMER, CLIMATE RESILIENCE, WATER AND BIODIVERSITY CONSERVATION ETC. , Yes it need patience and continuous efforts.

Let us just make conditions favourable for nature to work. after all all biological( including agriculture ) is a nature's business only and we are workers and consumer ( or recycler) of this business house.

____________________________

3. yes, this is a mis-argument that plant can not differentiate the source of nutrient that does not mean to feed anything without considering the system as whole, even our tongue cannot differentiate poison and non poison material but still we take care about that.This is rather a argument to promote the business of chemicals. If we go in depth of science plant sense/ realise the good and bad for them but they are helpless.

________

My intention for Putting these questions for the members was to get their views, spread it among the others so that all apprehensions and doubts need to cleared. Some of the replies were based on data of various sources, or assumption without getting field experiences that never works.

I am thankful to all the sincere participants specially Nao Lincoln and KS Reddy.

I choose this date of world environment day (5 June) as the organic/ ecological farming can contribute to great extent for conserving and improving environment.

Thanks a lot, if any of the viewers has real experience please reply in my another question of long term organic farming.

Please see detailed information about many of the queries about organic farming in my paper  entitled "Organic Agriculture Programming for Sustainability in Primary sector of India: Action and Adoption"  at  http://www.authorstream.com/Presentation/arun%20k-2215402-productivity/  or at     http://orgprints.org/26657/

In all entirety and in holistic sense, non human population in every context and imagination far exceeds that of human on Earth if not else where. Whereas, most of the non human species are the silent, sad and helpless sufferers when it comes to sharing of food and shelter resources on Earth. This is simply because of human arrogance of superiority over non humans. It is high time this attitude should die once for all i.e., before nature exhibits its fury as it is already getting manifested as floods, drought, earth quakes, tsunamis, virulence of diseases of unknown etymology. It is in this context, that truthful organic farming systems become pertinent if not indispensable.

I am sorry, I am not a >5 yrs' experienced person to add anything here. I am just learning about these farming systems now. My PhD  work is  comparing organic farming with conventional in terms of ecosystem services. May be because it is not that important to talk about  all the 'ecosystem services' that organic or conventional farming system provide, NOBODY here talked seriously about those services(except some people talked about soil nutrients). How about pollination services provided by those diversified organic farming (vs monoculture based conventional)? Why do people forget about their protein/fiber/oil rich foods pollinated by our pollinators? How about the roles of other beneficial insects like ground beetles (carabidae), parasitoids, and naturals enemies ? Do they not have any role of providing ecosystem services in organic agroecosystems? I do not understand why people (yes, even the educated, experienced people) do not care about other 'ecosystem services' but only talk about yield? Unless we have a overall economic valuation, comparing only the crop yield between two farming doesn't make any sense for our sustainable agriculture industry. I hope people will answer these questions too?

Knowledge and Humility are two sides of the same complimenting each other. The reflections of truly knowledgeable persons exude sincerity of purpose and ardent commitment to the cause of wisdom with extreme reverence and humility. 

I tried to make  a balance paper  about tangible and non tangible( Ecosystem services) and  between sustainability and profitability   in my paper. Please see at  http://orgprints.org/26657/

Dear Dr. Sharma,

1. not sufficient organic inputs are available: totally agree, specially in livestock farming.

2. yield level goes down with organic systems or is not comparable to chemical farming. It is true in the short-term and in 'conventionalized' organic farms (with simplistic management, just to comply with organic standards -i.e. input substitution-). Regarding the long-term there are different opinions, generally supporting the idea of similar and even higher production levels, and with extra outputs (social and environmental services). Regarding this last point, we should think about how production/productivity is measured: are ecosystem and social services (that also positively influence productivity in the long term) taken into account?

3. Plants can't differentiate between the sources of nutrients i.e organic or inorganic. When discussions come to organic products quality, I prefer to focus the conversation of food safety (chemical residues) instead nutritional quality. The reason is that organic farming is not an unique type of production as it allows/embrace many farms management practices and structures, so that I strongly think that products quality depends of the productoin system (its structure and management) and that this is not a consequence of just being certified as organic.

Regards,

Alfredo J. Escribano.

Now after one year gap  I hope most of us agree that 

1. There is no shortage of organic inputs rather the problem is distribution and efficient +  integrated use.

2. Many of the scholars supported that  total output of organic system has been been NEVER  recorded lower than conventional system. This aspect is more discussed in my other question can we compare organic to conventional in terms of yield only ? please see

3.Dr Lincoln given nice reply that  yes, plant as a system can differentiate  source of  nutrient in terms of effect.

Thus  with this whole discussion I may draw a conclusion that  all the three apprehensions are not true  and organic system, if manage prudently ,able to ensure long term food security, soil health and climatic resilience.

I mostly agree with Arun's conclusion above, But again, we need to see in a holistic approach. Why should we compare yield only? There are several other ecosystem services that we need to consider while comparing these two systems. It depends on the context too, since there are many different "types" of the organic or conventional systems. We will get mixed answers if we generalize the case.

When long yard bean attack by aphid, the only way to manage them is by applying insecticide. So I think organic long yard bean farming possible when there is no aphid incidence happened.

Dear Arun,

Below your 3 statements/arguments are my comments.

1. not sufficient organic inputs are available

This should not be a problem for organic agriculture because with this method of farming recycling/composting on site at the farm become a must do practice. Besides this there are many agronomic practices that include: crop rotation, green manuring, companion cropping that aim at regenerating as much as possible soil fertility.

2. yield level goes down with organic systems or is not comparable to chemical farming

This statement is refuted by several studies from the Rodale Institute in the US and others that proved that the yields of organic agriculture are comparable to those of conventional farming.

3. Plants can't differentiate between the sources of nutrients i.e organic or inorganic.

I would say here that plans respond beautifully to nutrients that are easily accessible (ex. water soluble) making synthetic fertilizers (salts) very effective in growing plants (when irrigation water is available too). However, the fertility approach embraced in organic farming consists in 'feeding' the soil bacteria first. When the soil microflora is abundant and diverse, then the metabolism carried out by the soil biology will facilitate the process of humification and with it the solubilization and accessibility of nutrients for the plants.

1. There is sufficient organic materials available, It is the photosynthesis that regulate the net primary productivity.

2, Yields will often go down when converting from high-input systems, but can often increase when converting from low input systems. There are many ways to influence yields in farming and this is not a major limitation for oa. In addition, the overarching problem for farmers of the world is overproduction....

3.Most nutrients are mediated by microorganisms and they are certainly impacted by the form nutrients are in.