Soil health improves if we are able to synchronize supply of nutrient from soil and fertilizer/manure to crop plants. Is it a must for maintenance of soil health? If yes, are blanket nutrient recommendations for large regions resulting in slow soil health decline?
DEAR SIR
YES , it is a must for maintenance of soil health. I assume it indispensable.However , keeping in view of present productivity levels , specifiaclly for rice-wheat in North India;I seldom FEEL THAT BLANKET RECOMMENDATIONS ARE CAUSING SLOW HEALTH DECLINE.
‘You do not get something for nothing’; ‘You get out what you put in’. These simple phrases are usually applied to life in general but are very relevant to nutrient management in agriculture. Farmers have known for many years that they need to replace nutrients removed in crop plants to maintain soil nutrient levels, i.e. maintain a nutrient balance, and that some soils need those levels increased if sufficient food is to be grown and land kept fertile—what is often described as ‘in good heart’. Before man-made fertilizers became widely available, there was usually a deficiency of nutrients, and yields of crops such as wheat were small and very variable.
Mr. Kulvir Singh, I appreciate your observations and comments but need more elaboration in terms of optimising fertilizer management for maintaining/improving soil health. I hope you will like to further elaborate.
Sir,Thanks for your response.
I will be a part to further deliberations on this question.
regards
Interesting issue , you have raised , which is the very basis of improved fertilizer-use-efficiency. We assign maximum weightage to this issue while scheduling fertigation requirement of any perennial fruit crops, so is the case even with annual field crops. Unfortunately soil health-related issues are least addressed..
Partitioning of nutrient requirement of a crop across crop phenophases is to be experimented, instead of guessing this issue, then only the objectivity of synchronization of nutrient demand versus application could be fulfilled. Unfortunately , this issue is least addressed with organic manures or green manures to see the nutrient release versus demand in a crop across different growth stages..but soil health -related issues are invariably addressed
Here are some work of ours , hope you like them...
Hello Dr. Bijay Singh, I just came across your questions and wanted to share my knowledge on it. Here are my views...
How much is role of synchronization of nutrient supply from soil and fertilizer/manure to crop plants for maintenance of soil health? There are several studies which show that excessive N application can lead to carbon burning which is one indicator of soil health. I don't know how many years would it take to deteriorate soil physical health across soil types and cropping systems. There are also several studies showing that over fertilization can lead to decrease of AMF, an important proxy of soil health. There are other indicators of soil health that are related to nutrient management which should be discussed in more details. For example, work from NCSU shows that soil physical health deteriorates with mismanagement of nutrients but mainly from nitrogen. There is hardly any work done on P and K response to soil health.
Soil health improves if we are able to synchronize supply of nutrient from soil and fertilizer/manure to crop plants. Is it a must for maintenance of soil health? If yes, are blanket nutrient recommendations for large regions resulting in slow soil health decline? The answer is yes to the first question and no to second. site-specific nutrient management is important but depends upon the region. For example, there are areas in the world that have homogenous soils across large acreage and very less gradient in weather. If cropping systems are similar then site-specific nutrient management might not be needed, otherwise it is warranted.
Synchronisation of fertilization with crop growth stages is more precise with chemical fertilizers than organic manure.However , nutrient release pattern is most important which depends upon whole range of soil properties and management practices...
Dear Dr. Farmaha, I am very pleased to read your thoughts and I fully agree with what you have said. What do you think the time has come that we should try to introduce site-specific nutrient management (SSNM) wherever it is possible. I believe, SSNM and soil health go hand-in-hand as for as nutrient management is concerned.
Righlty said Sir( Bijay Singh) through SSNM we can syncronize the nutrients demands of crop and supply. Balance use of nutrients , supply of nutrients when demand of crop is high like grand growth stage gives good results in term of NUE and yiled. Even simple step i.e spit doses of N is very beneficial to enhance NUE. Now time has also come to enhance the phophous use efficieny because of high price of phophatic fertilizers in India. We should also thing to utilize available phophorus in soil by uing PSB or other means.
SSNM , i feel , it should serve the purpose in maintenance of soil health ( Nutrient reserve ) , since this strategy is primarily based on plant nutrient uptake and secondly , it will address more effectively towards any possible nutrient mining ( Nutrient export from the field ) in a more precise way . But , unless there is a simultaneous comparison of conventional soil test -crop response versus SSNM , i feel , its difficult to opine . The most important of all while executing the SSNM , is the measurement of spatial variability in soil fertility and later imposing the variable rate of fertilizer application. Prior to that , we need to optimise proper grid size for soil sampling, based on which, soil fertility variograms would be developed.
I am not too sure, whether or not , we have that kind of expertise to execute SSNM at field level to replace conventional mode of nutrient management stratergy. However, SSNM has produced some wonderful results even in perennial fruit crops...
Your question brought one question in my mind. What is soil health? How do we define a healthy soil? What are the criterion to look for? Or the other way, what is an unhealthy soil? (Sorry to be asking the cross question, but I was wondering, and perhaps too curious)
Dear Dr. Bijay Singh,
Thanks for your response. Yes, we should further enhance our knowledge of SSNM and demonstrate to communities its benefit across scales and systems. I also agree with you that proper nutrient management is part of improving soil health and example is relation of nutrient management with soil acidity.
We are seeing a new era of innovation of agriculture intelligent technologies. We should take benefit of these technologies in achieving increased farm input-use efficiencies. These technologies can also help us to improve model simulations and increase the scale of SSNM practices.
Sincerely,
Bhupinder
GOOD UPDATES FROM BHUPINDER AND SRIVASTAVA.
Measurement of spatial variability in soil fertility is definitely important.
In the light of above said,can we imagine that the way with which soil health cards are being prepared under federal govt. sponsored program across India will be really useful to address SSNM issue.
Please have a look at enclosed review , quite revealing indeed...
Thank you, Dr. Srivastava for sharing the publication. I will take a look at it. In fact, i have to give an extension talk to beginning farmers next week and may be able to use some of your work. I hope to meet you some time. Please shoot me any email if you plan to be in US.
Regards,
Bhupinder
It will be my pleasure and pride both....lets hope Dr shaab...
I am already working on a book chapter on optimizing fertilizer management and soil health. I will share it when it is ready. It should answer many concerns raised by different participants linking fertilizer use with soil health. A general document (unfortunately it does not deal with SSNM in details) on fertilizer management for enhancing soil health is attached herewith.