Effect Of Moisture Levels And Fertilizer Rates On Growth Yield And Water Use Efficiency Of Upland Rice

Introduction of NERICA New Rice for Africa upland rice has been projected to transform rice farming in stress-afflicted ecologies by producing high yield with minimum inputs. This has not been realized due to the vulnerability of upland rice cultivation to yield limiting constraints such as inadequate water control and low soil fertility particularly in sub-Saharan Africa. The study was carried out in a greenhouse environment to determine the effect of water levels fertilizer rates and Water use efficiency of NERICA 1 rice variety at KALRO-Mwea in two cropping seasons of 2017. Two water levels 3.5mm day-1 7.00mm day-1 and sixteen fertilizer rates encompassing four levels of phosphorus 0 20 40 60 kg P2O5 ha-1 from Triple super phosphate and four levels of potassium 0 10 20 30 kg K2O ha-1 from murate of potash were applied. The experiment was laid up in split plot design with three replications with water levels assigned in the main plot and fertilizer rate in sub-plot. Growth parameters measured were plant height number of tillers and number of leaves while yield indicators used were panicle weight spikelet fertility 100 grain weight grain length 26 width plus grain yield. The data collected was summarized in MS Excel and analyzed using SPSS version 23 for ANOVA and post-hoc tests at 5. Water levels significantly affected growth parameters grain yield and WUE. The highest grain yield of 4.535.57 kgha-1and 2705.1kgha-1 was attained with 7.00mmday while 3.5mmday significantly gave higher WUE of .75 kgha-1m-3 and .53 kgha-1m-3 in season 1 and 2 respectively. Highest grain yield of 3.745.41kgha-1 was attained by P1K2 0 kgha-1 P2O5 0 Kgha-1 K2O fertilizer rate P3K3 40 kgha-1 P2O520 Kgha-1 K2O fertilizer rate gave the highest WUE of .69 kgha-1m-3 average of the two seasons. P3K3W2 40 kgha-1 P2O520 kgha-1 K2O-7.00mmday water fertilizer interaction significantly gave highest grain yield of 4114.2 kgha-1and highest WUE of .86 kgha-1m-3 was attained in the interaction P1K2W1 0 kgha-1 P2O5 10 kgha-1 K2O-3.5mm day-1. With 3.5mm day-1 it is possible achieve over 75 grain yields as can be attained with rainfall of 833 mm 7.0mm day-1 in soils not deficient of phosphorus and moderate Potassium plus sustained Nitrogen supply of 60 kg ha-1. While considering the economics WUE growth and yield parameters application of P1K2 0 kgha-1 P2O5 10 kgha-1 K2O with 3.5mmday appears to the viable option for NERICA 1 rice in loam sandy soils of Kirogo -Mwea.