Abstract
To study the long-term effect of lantana (Lantana camara L.) addition and N application on crop yields and N uptake in rice-wheat cropping, an experiment was conducted in the wet season (July-November) of 1988-95 with four levels of lantana (0, 10, 20, and 30 t ha-1 on fresh weight basis) and three levels of N at Palampur, India. Lantana biomass was added only to rice 10 to 15 days before transplanting and (or) puddling each year. The levels of N were 45, 67.5, and 90 kg ha-1 to rice (i.e., 50, 75, and 100% of recommended dose). The order of these three N levels was reversed during wheat to 120, 90, and 60 kg ha-1 (i.e., 100, 75, and 50% of the recommended dose). The yield and N uptake by both rice and wheat increased significantly with the additions of lantana and N. The average increase in yield over the control was about 11, 18, and 22% in rice and 11, 21, and 29% in wheat with the addition of 10, 20, and 30 t ha-1 lantana, respectively. Similarly, the increase in rice yield was about 7 and 14%, and in wheat, 10 and 12% with 75 and 100% of the recommended N over its 50% recommended dose. The correlation studies revealed that NH4-N in rice and NO3-N in wheat were the most important N fractions contributing to N nutrition of rice and wheat, respectively, and that amino acid N was the next in importance in both the crops.
