Nodulation and N-fixation by legumes grown as inter-crops of sugarcane and their effect on sugarcane Production

To study the nodulation pattern of legumes grown as inter-crops of sugarcane and their effect on cane yield, two field experiments were conducted at the Indian Institute of sugar- cane Research, Lucknow, over a period of 4 years (1977-80), Number and weight of nodules increased upto 30 days after sowing and declines thereafter in green gram (vigna radiata (L) wilczek Cv. Pusa baisakhi) and black gram (vigna mungo (L) Happer Cv, Type 9). Increasing trend in both these twe characters was observed upto 60 days in pigeonpea (cajanus cajan (L) Milsp. Cv. Type 21). The rate of decrease in nodulation of green gram and black gram was faster in inter-cropping system due to shading caused by lateral spread of sugarcane. N application to pigeonpea. and to sugarcane proved deleterious for nodule development of green gram and black gram. Inter cropping of black gram decreased the cane yield compared to pure sugarcane supplied with P. Autumn sugarcane planted in between standing crop of pigeonpea yielded highest at 40 Kg N/ha applied to pigeonpea and 150 Kg N/ha applied to sugarcane.