Crop yield, disease incidence, and insect pest attack in relation to N dynamics in rice

摘要

The decline in rice yield on the Indo-Gangetic plains is a matter of great concern (Abrol et al 2000), We evaluated available soil N, plant N content and uptake during rice growth, and incidence of major diseases and insect pest attacks in an ongoinglong-term experiment (since 1982) at the PAU farm (30~o 562 N and 75~o 272 E). The experimental site is characterized as semiarid subtropical, with soil pH of 8.1, electrical conductivity of 0.18 dS m~(-1), 0.21% organic carbon, 3 kg NaHCO_3-extractableP, and 93 kg NH_4Oac-extractable K ha~(-1).