Productivity and profitability on cotton-based production systems under organic and conventional management in India

摘要

The debate on the relative benefits of conventional and organic farming systems is more topical than ever. The achievements of conventional high-input agriculture were based to a large extent on fossil fuels and largely brought about at the cost of deteriorating soil fertility. Developing more sustainable farming practices on a large scale is of utmost importance. However, information about the performance of farming systems under organic and conventional management in tropical and subtropical regions is sparse. This study presents agronomic and economic data from the conversion phase (2007-2010) of a farming systems comparison trial on a Vertisol soil in central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without genetically modified (GM) Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the first crop rotation (cycle 1: 2007-2008) for cotton (-29%) and wheat (-27%), whereas in the second crop rotation (cycle 2: 2009-2010) yields were similar in all farming systems. Lower variable production costs in organic farming systems (-32%) led to similar gross margins in all systems, averaging 104’909 Indian rupees ha-1 (equivalent to 2’089 US Dollars ha-1) per crop rotation. Conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%). Our findings show the potential benefits of organic farming systems under the premise that marginal farmers have access to knowledge, purchased inputs such as organic fertilizers, pesticides and non-GM seeds, and assuming that there is a market demand and well developed certification system. Future research needs to focus on the verification of our outcomes in further crop cycles, on geographically spread on-farm comparisons, and on the ecological impact of the different farming systems.