Additive intercropping with peanut relay-planted between different patterns of rice rows increases yield of red rice in aerobic irrigation system

Abstract

Rice yields under conventional techniques are very low without high doses of commercial fertilizer application, while intercropping with legumes can increase yields. This research aimed to examine the effect of relay-planting peanut between rice rows of different patterns on yield of red rice in aerobic irrigation systems, by conducting a field experiment designed according to Split Plot design with two treatment factors, i.e. intercropping as main plots (T0= without; T1= intercropping with peanuts), and rice row patterns as sub-plots (P1= normal or single-row; P2= double-row; P3= triple-row). In T1, one row of peanut was relay-planted (additive series) between single, double, or triple rows of red rice plants three weeks after seeding red rice on raised-beds. Results indicated that additive intercropping with peanut significantly increased clump size, dry straw weight, filled panicle number, panicle length, total biomass, filled grain number, grain yield per clump, and harvest index, and reduced percentage of unfilled grains of red rice , while patterns of rice rows only affected dry straw weight, percentage of panicle number, and weight of 100 grains. However, there were significant interactions between the treatment factors on dry straw weight and percentage of panicle number, which under single-row, they were low in monocropping but high and no differences between row patterns in intercropping system. Similarly, grain yield was lower in single or double row than triple row pattern under monocropping but significantly higher and no differences between row patterns under intercropping, indicating the highest benefits of intercropping under single row pattern.