Effect of Mini-Sprinkler Irrigation on Yield of Two Hybrid Maize Varieties under Two Levels of Fertilization on Dryland of Nangakara Area, Sumbawa, Indonesia

With the construction of a dam and its irrigation canals in the irrigation area of Nangakara River, in Pekat district of Dompu regency in West Nusa Tenggara Province (NTB), Indonesia, it was necessary to carry out an irrigation water management test farm, for use as a basis for making recommendations and as a demonstration area for the farmers. This study aimed to examine the effect of two different irrigation techniques, between sprinkler (LSI) and surface (CSI) irrigation, and two fertilization packages, on yield of two hybrid maize varieties on dryland with sandy soils. The experiment was organized according to Split Split-Plot design with three blocks and three treatment factors, namely hybrid maize varieties (Bisi-2 and C-7) as main plot, irrigation techniques (LSI and CSI) as sub-plots, and fertilizer doses (F1= low level; F2= moderate level) as sub-sub-plots. The results indicated that there were no significant interaction effects among treatment factors, but there were significant effects of both irrigation techniques and levels of fertilizer doses on all observation variables, except for the weight of 1000 dry grains. In general, both the higher level of fertilizer doses (F2) and application of sprinkler irrigation (LSI) resulted in higher dry grain yield, water use efficiency (WUE), weights of harvested ears and harvested stover. However, the C-7 variety showed higher response to fertilizer doses especially under sprinkler irrigation. On average, grain yield was significantly higher under sprinkler (12.54 ton/ha) than surface irrigation (10.17 ton/ha), indicating the disadvantages of surface versus sprinkler irrigation. The harvested stover weight was higher on Bisi-2 (21.19 ton/ha) than on C-7 (13.98 ton/ha), but the dry grain yield tended to be higher on C-7 (12.0 t/ha) than on Bisi-2 (10.7 t/ha), indicating that C-7 was higher in the rate of assimilate partitioning into seeds than the Bisi-2 variety.