Performance of Upland Rice Intercropped Legumes and Level of Nitrogen Fertilizer

Abstract

Upland rice, a key food source for farmers, is often studied to improve food production. This study aims to determine the optimal level of nitrogen required for upland rice under intercropping system and to determine suitable legumes that complement for the growth and yield of upland rice base intercropping. The experiment involved two factors where factor A consists of levels of nitrogen, and factor B consists of a cropping system. Measurements included leaf area index, dry matter yield, land equivalent ratio for rice and legume. For rice, the number of panicles, field grains per panicle, 1000-seeds weight, and yield; and for legumes intercropped is the number of branches and pod per plant, seeds per pod, 100-seeds weight, and seed yield. The best results were achieved when rice was grown with cowpeas and fertilized with 60kg of nitrogen per hectare, producing a rice yield of 1,492kg per hectare. Cowpea intercropping also showed a 26% increase in land equivalent ration (LER of 1.26) compared to growing rice alone. These were attributed to a high number of filled grains per panicle and 1000 seed weight. Growing rice with mungbeans resulted in a higher mungbean yield over cowpea of 819.54kgha-1. However, the aggressive growth of mungbean by having more parallel branches and high LAI caused intense shading to its rice counterpart, which resulting in lower rice yield of 878.70kgha-1 and lower LER of 0.99. Therefore, the most suitable legume for intercropping rice is cowpea because it complements upland rice growth.