A three years field experiment consisting of six cropping treatments applied during both seasons was conducted during 1997-98 to 1999-2000 to study the effect of nitrogen and legume intercropping with maize for sustainability of maize-wheat cropping systems. These treatments included: viz; sole maize (Zea mays L.) at 60 cm rows, sole maize with FYM@10 tons/ha, maize intercropped with blackgram (Phaseolus mungo L.) or soybean (Glycine max ( L) merr.) in paired rows (30/90 cm) in 2:2 row ratio, normal planted maize(60 cm) intercropped in 1:1 row ratio with pigeon pea (Cajanus cajan (L.) Millsp.) or blackgram under rainfed condition followed by irrigated wheat during rabi season with three N levels(40,100&160 kg N/ha). Intercropping treatments was not significantly influenced by grain yield and yield attributing characters of maize while grain yield and yield attributing characters of subsequent wheat crop increased significantly under FYM or intercropping treatments over respective check. Wheat yield significantly increased up to 160 kg N/ha. However, there was no significant increase in yield of maize beyond 100 kg N/ha. The maximum maize equivalent yield of rotation (75.65 q/ha) was found in 2:2 maize-soybean row ratio with the highest net return of (Rs. 23,670/ha) and B:C ratio (1.99). Sole maize-wheat rotation showed a decline in soil organic carbon by 3.84%, while black gram and soybean intercropping with maize in paired rows (2:2 row ratio) followed by wheat increased contents of per cent organic carbon in soil as 0.65 and 0.67, respectively, compared to initial values of 0.52 per cent. Plots treated with intercrops/FYM during the rainy season sustained the wheat yield while the check plot showed a decline in wheat yield by 9.12% at the time of completion of study. Nitrogen balance under different intercropping treatments was calculated. The highest buildup of soil N i.e. 132 kg N/ha was computed under maize-soybean intercropping in paired rows in 2:2 row ratios(30/90 cm) followed by wheat. Contribution of intercrops to fix atmospheric nitrogen during three years of experimentation was computed by formulae given by Lyon & Bizzell (1934) for intercropping treatments which varied from 109 to 172 kg N/ha. Soybean intercropping with maize in paired rows in 2:2 row ratios contributed maximum atmospheric nitrogen in the soil and sustained the production level of maize-wheat cropping system.

English

0501|AGRIS 0501|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Publications Collection