Globally, there is an increasing concern for environmental sustainability and availability of safe and nutritious food. Organic agriculture is seen as a promising solution to address these concerns. There are many definitions of organic agriculture but all converge on the point that it is a system that relies on ecosystem management rather than on external agricultural inputs. Although the arguments regarding eco-system health and nutritious food in organic production are contested, there are some convincing results about low levels of chemical residues in the produce of organic farms as compared to conventional farms.

Two key areas where we need to understand the implication of organic agriculture as opposed to conventional agriculture are soil fertility and plant health. Management of soil health without the use of any form of synthetically manufactured fertilizers (such as urea, diammonium phosphate or DAP) is emphasized in the discussion of organic farming. The second area pertains to plant health, both in terms of safe food production as well as the management of pest and disease attacks. In organic agriculture, plant health can be ensured only through other management practices (biological, mechanical, agronomic) without using synthetic chemicals for plant protection (such as synthetic pesticides or herbicides).

Soil Health

In order to develop a clear understanding about health of Indian soils, we have to critically examine the district soil fertility maps for 19 States of India released by the Indian Institute of Soil Science, Bhopal, in 2014. The assessment revealed that 59 per cent of soils are deficient in nitrogen (N), 49 per cent in phosphorous (P) and 9 per cent in potassium (K) in 19 states of the country. Along with deficiencies in these three major nutrients, there are many districts with low level of secondary nutrients (calcium, magnesium and sulphur). Further, many districts of the country also have micronutrient deficient soils. The application of organic or inorganic fertilizers has to be linked to the type of deficiency in soil nutrients For instance, as Dr. Mangala Rai, noted, “when micro-nutrients and secondary nutrients are decreasing, we won’t get appropriate response even if you keep on applying nitrogen, phosphorus and potash.” (Ministry of Agriculture 2015, p. 18)

A serious concern in the area of soil health is imbalance among major soil nutrients (NPK). For major nutrients, the ideal balance is 4:2:1 for N:P:K . However, there is imbalance in the NPK ratio in most soils in the country. According to Dr. Mangala Rai, imbalanced use of fertilizers has led to the situation of a NPK ratio of 7:3:1 … and it is essential to apply organic inputs (ibid., p.19).

Results generated from long-term fertilizer experiments across various soil types are insightful. Experimental results reveal that balanced use of nutrients maintained nitrogen status at par with the initial status. In many locations, the balanced application of nutrients not only maintained micronutrient status but also increased the content of micronutrients in soil. Data accumulated through these experiments clearly indicates that there are improvements in microbial population and enzyme activity after the application of chemical fertilizers. The results from these experiments disprove the notion that application of fertilizer results in a reduction of soil organic carbon. Analysis of data also revealed that only conjunctive use of chemical fertilizers and farm yard manure always maintained, within the context of the experiments, a large amount of organic carbon in the soil across different types of soil. Further, the long-term fertilizer experiments clearly bring out the fact that it is not possible to sustain productivity without external supply of nutrients (Singh and Wanjari 2013, p. 9-10).

So the issue which should be at the forefront in terms of soil health is the application of recommended and balanced dose of nutrients to the soil, based on an analysis of soil nutrient deficiencies. This can be achieved through the widely accepted approach of Integrated Nutrient Management (INM) with a combination of organic and inorganic inputs in order to attain an optimal level of soil health.

Plant Health

There are numerous pests and diseases that attack plants. In organic agriculture, pest and disease management is mainly done through non-chemical control measures like biological or mechanical. There are several success stories pertaining to effective biological control by using Trichderma spp. against various soil borne diseases. Similarly, mechanical traps can be effectively used against controlling insects like whitefly and leafhopper. Although, a variety of non-chemical measures are available for disease and pest management, it is very challenging to control a sudden outbreak of pest and disease without using chemical measures.

There are many other challenges to be dealt with in bio-control and in other non-chemical measures. Issues relating to the proper application, storage capacity and transportation of bio-control agents need to be addressed and standardised. Moreover, there is a gap in demand and supply of both bio-fertilizers and bio-pesticides (Ministry of Agriculture 2015, p. 31-34).

Given this situation, without a huge leap forward, non-chemical control of plant health management in the country is difficult. Integrated use of chemicals along with other measures will be a wise prescription for the farming community to deal with the issue of plant health.

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In order to achieve sustainability in the production system, we need develop a clear understanding regarding availability and imbalance of soil nutrients (major, secondary and micro nutrients) and each specific deficiency has to be addressed separately. The question is the correct use of integrated use of inputs rather than the total rejection of chemical fertilizers. Pest and disease management through solely non-chemical measures (and this would include resistance breeding and genetic modification) is currently difficult especially at the time of sudden incidence of pest and disease.

In my view, integrated management practices should be followed to address the concerns of both plant and soil health in the Indian context.

As Dr. M. S. Swaminathan has noted:

The challenges in organic farming are (a) replenishment of soil fertility, and (b) plant health management. Thus, both soil health and plant health management requires interventions which will have to be tailored to the cropping/farming system … Unfortunately, the available organic manures are not adequate to achieve higher productivity. Farm size is getting smaller and hence for small farmers, the organic methods will be integrated nutrient supply and integrated pest management. (Ministry of Agriculture, 2015, p. 20)

A hasty conclusion, about which farming practice is better (organic versus inorganic), will not lead us to a comprehensive understanding of the issue. Rather, we need to use best available scientific practices to achieve soil health and plant health.

References

Ministry of Agriculture (2015), Ninth Report- Committee on Estimates, National Project on Organic Farming, presented to Lok Sabha on August 13, New Delhi, available at http://www.indiaenvironmentportal.org.in/files/file/national%20project%20on%20organic%20farming.pdf.

Singh, Muneshwar and Wanjari, R. H. (2013), Annual Report – 2012-13, All India Coordinated Research Project on Long-Term Fertilizer Experiments to Study Changes in Soil Quality, Crop Productivity and Sustainability, AICRP – LTFE, Indian Institute of Soil Science (ICAR), Nabibagh, Bhopal, available at http://www.iiss.nic.in/downloads/ANNUAL%20REPORT%202012-13.pdf.