Review of research on INM and various weed control practices in rice (Oryza sativa L.)-Groundnut (Arachis hypogaea L.) cropping system under irrigated medium land situation

Rice-groundnut cropping system is one of the important cropping systems of India. Rice (Oryza sativa L.) is the staple food of the world. Rice is a heavy nitrogen feeder, but fertilizer nitrogen use-efficiency is very low under tropical conditions. Nutrient management provides an approach for feeding the plants with nutrients as and when required. It is therefore, necessary to apply fertilizer elements particularly N, P and K in optimal quantity to increase and sustain the productivity. A major portion of nitrogen in wetland soils occurs in organic pool, though this is usually low. Complementary use of organic and biological source of plant nutrient along with chemical fertilizer is of great importance for the maintenance of soil health and productivity. Sustainable cropping systems require crop yields should be stable through the maintenance of soil fertility and the balance of nutrients in the system. Increases in soil carbon levels require sustained periods of balanced fertilization and residue retention. Weed infestation in rice remains the largest constraint, limiting its productivity. Groundnut (Arachis hypogaea L.) is one of the most important edible oilseed crop extensively cultivated in the world. This groundnut is highly susceptible to weed infestation because of its initial slow growth habit up to 40 days after sowing, short plant height and underground pod bearing habit. In this review studies on the effect of integrated nutrient management and weed control practices on rice (Oryza sativa L.) – groundnut (Arachis hypogaea L.) cropping system are discussed. Judicious application of chemical fertiliser coupled with green manuring of Dhaincha and use of herbicides in rice as well as succeeding groundnut crop for management of weeds increases the productivity of the system.