EFFECT OF APPLICATION OF RICE STRAW COMPOST AND NPK FERTILIZERS UNDER SOME IRRIGATION REGIMES ON GRAIN YIELD AND WATER PRODUCTIVITY OF EHR1 HYBRID RICE CULTIVAR

Abstract

Two field experiments were carried out at the Experimental Farm of Rice Research and Training Center (RRTC), Sakha-Kafr El-Sheikh, Egypt, during 2010 and 2011 summer seasons. The objective of this research was to investigate the effects of NPK fertilizers with rice straw compost on growth and grain yield, as well as water productivity (WP) and nitrogen use efficiency of Egyptian hybrid rice cultivar (EHR1) under different irrigation regimes. A split plot design, with four replicates, was used in all experiments. The main plots were devoted to three irrigation regimes; namely, continuous flooding (CF) and irrigation to 5 – 6 cm depth three (3-) and six (6-) days after disappearance of surface water (DADSW). The sub-plots were occupied by six fertilizer treatments; namely, zero fertilizer (T1), 100% of recommended NPK fertilizer (T2), application of two t/h rice straw compost + 25% NPK (T3), 50% NPK (T4), 75% NPK (T5) and 100% NPK (T6). The main results indicated that CF and 3-DADSW treatments registered significant and higher values of growth attributes, grain yield and most of its attributes, as well as protein content and N-uptake, compared with 6-DADSW treatment, except for number of days to 50% heading and unfilled grain (%). Dry matter, LAI, plant height and grain yield and most of its attributes, as well as protein content and N-uptake, were significantly enhanced by the application of 100% NPK, along with rice straw compost at two t/ha (T6), which was at per with T2 (100% NPK) and T5 (75 % NPK + 2 t/h rice straw compost). Under all irrigation regimes, application of NPK fertilizer, either alone or with rice straw compost, recorded higher grain yield and WP than the control treatment. CF consumed the highest amount of irrigation water, while, application of 3- and 6-DADSW tended to decrease the amount of water used. Furthermore, 3-DADSW recorded the highest WP (0.84 and 0.86 kg/m3) and the minimum grain yield reduction (4.59 and 6.41 %) with water saved about 11.55 and 11.12 % compared to CF in both seasons, respectively. Generally, under the same experimental conditions, it was concluded to use 3-DADSW irrigation with adding 75% NPK, along with rice straw compost at two t/ha for reasonable grain yield and high WP, as well as it could decrease chemical fertilizer input by 25 % from the present recommended application without decreasing rice grain yield.