Department of Soil Science and Agricultural Chemistry, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu
An assessment of the accumulation of nitrogen in a black soil after six continuous crops in a long-term field experiment was made. The availability of N increased substantially over years by increasing the rate of application of N along with P. Adding N alone did not improve the position and was observed to be not necessary in a cropping system where a legume (cowpea) is included in rotation.
Continuous cropping, changes in soil N status, black soil
