Organic rice-prawn aquaculture (#journal)

Organic rice–prawn farming yields 20% higher revenues

Organic farming of rice and giant river prawns in rotational crops was tested in the waterlogged paddy fields of Kuttanad, Kerala as part of the Indian Organic Aquaculture Project. Rice was cultivated during November to February, followed by a crop of freshwater prawns in the same field from March to September. Farming rice organically reduced yields by 23 %. However, the organic prawn crop yield was 10 % higher than the yield of the conventional system, so although organic rice farming realized lower returns than conventional, its combination with organic prawn farming enhanced net revenue by 20 % over conventional rice/conventional prawn production.

Winter legume rotation improves rice yield (#journal)

Winter legumes in rice crop rotations reduces nitrogen loss, and improves rice yield and soil nitrogen supply

Intensive irrigated rice-wheat crop systems have caused serious soil depletion and nitrogen loss in  China. A possible solution is the incorporation of legumes in rice, but little is known on the impact of legumes on rotation, soil fertility, and nitrogen loss. This study considered the effect of five rice-based rotations on soil nitrogen, rice yield, and runoff loss. Results show that replacing 9.5–21.4 % of nitrogen fertilizer by rape, vetch or bean residues maintained rice yields, and using legumes as a winter crop in rice-bean and rice-vetch combinations increased rice grain yield 5 % while decreasing nitrogen runoff 30–60 %.