Here the yields of crops grown by low-cost inputs including plant biomass are compared with chemical fertiliser-induced production.
The study was conducted over 1999-2004, and the findings conclude that the yields of low intensive biological farming are as good, if not better than chemical fertiliser intensive farming.
The authors observe that mechanical and chemical intensive irrigated agriculture is not only expensive but also can undermine the water security of future generations. Modern agricultural techniques combined with traditional agricultural practices can make crop production more sustainable and still achieve high productivity.
The experiment was designed using a combination of techniques reported in various journals and traditional knowledge. The techniques include using crop residues and other biomass as surface mulch and biologically-based approaches to enhance microbial activity in the soil.
Traditional knowledge that the experiment used, included soil fertility improvement by use of leguminous and non-leguminous plants, weeds that are beneficial to crop growth, use of plant extracts on crops at specific times etc.
The experiment designed also included the use of cattle. The authors state that such a system would be relevant to small and marginal farmers in developing countries in humid, sub-humid, and semi-arid tropics and also most farmers in India who have mostly small and marginal holdings.
Observing that the higher total returns of larger farms are due to the size of operation rather than from greater factor productivity or efficiency, the authors state that smaller farms can outperform larger farms.
The intention of the project was to examine if yields comparable to conventional agriculture can be achieved by techniques that are described in the above paragraphs. The experiment was multi-year and was designed to evaluate four systems of crop husbandry.
The first two cropping systems were low-cost systems where in addition to what was mobilized from soil biotic activity, crop nutrients were provided from biomass inputs. The third system was the conventional fertiliser system, while the fourth was a mix of conventional and alternative systems.
The authors then discuss the soil type and rainfall pattern of the region where this experiment was conducted. In each year of the experiment, different crops were grown. However between the four experiment types, the crops remained the same.
Details of the various nutrients added for each crop and experiment are provided. The authors also detail the changes in nutrient and bacteria level in the soil at various stages of the experiment. The paper has used many tables and graphs to not only explain the concept of the experiment, but also the outcomes.
One of the conclusions is that except for the first year, the net income from crops using the alternative farming methods was higher than from the conventional cropping method. This differential ranged between 1.3 and 4.6 times. There is however, a need to test such systems and carry out experiments, in different soil and climatic conditions.
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