relation: http://oar.icrisat.org/7529/ title: Nitrogen returns to soil by selected cropping systems on a Vertisol in the semi-arid tropics of India creator: Abdurahman, M D creator: Seeling, B creator: Rego, T J creator: Reddy, B B subject: Soil Science subject: Agriculture-Farming, Production, Technology, Economics description: Limited nitrogen (N) availability is a common constraint for crop production on Vertisols. Erratic rainfall in the semi-arid tropics and relatively high cost of N fertilizers make its application a risky investment, therefore, most farmers do not apply N fertilizer in dryland crops. Cropping systems which improve soil fertility can minimize the need for synthetic fertilizers. In a two-year experiment, four cropping systems and mirror images of two systems were examined for their returns of N to soil in roots and fallen leaves. Sorghum/pigeonpea intercrop for two years (S/PP S/PP) and cowpea/pigeonpea intercrop rotated with sorghum followed by safflower (COW/PP S+SAF) contributed around 54 kg N ha-1 in roots and fallen leaves when no nitrogen fetilizer was applied. The largest proportion of this N was returned to soil through fallen leaves of pigeonpea. In terms of root mass a rotation of sorghum followed by safflower in the post-rainy season (S+SAF S+SAF) deposited almost the same amount of N in roots if adequately fertilized. Under S/PP S/PP the soil mineral N content was measurable higher compared to other systems. publisher: The Gaurav Society of Agricultural Research Information Centre (GSARIC) date: 1999 type: Article type: PeerReviewed format: application/pdf language: en identifier: http://oar.icrisat.org/7529/1/CR_17_3_273-281_1999.pdf identifier: Abdurahman, M D and Seeling, B and Rego, T J and Reddy, B B (1999) Nitrogen returns to soil by selected cropping systems on a Vertisol in the semi-arid tropics of India. Crop Research (Hisar), 17 (3). pp. 273-281. ISSN 0970-4884