Use of carbonized rice hull for increased yield and water productivity

Ganotisi et al. (PhilRice) further evaluated the use of CRH[carbonized rice hull] in improving the productivity of sandy soils for growing mungbean during dry months (March to May) of 2004-2005. The study was conducted at the Palayamanan site in Currimao, Ilocos Norte [Philippines]. The second study determined the effect of CRH on the water productivity and yield of garlic grown in clay soils. It was conducted at PhilRice Batac Experimental Farm during the dry seasons of 2004-2006. Findings of the study revealed the following: Mungbean. Three different amounts of CRH were applied in the furrows: 10t/ha, 20t/ha, and 30t/ha. The crop was irrigated every 4 days during the seedling stage, every 5 days during the vegetative stage, and every 7 days during the reproductive stage. The application of 20-30t/ha of CRH increase the number of pods, number of seeds per pod, and consequently the yield. The application of 30t/ha yielded the highest at 715kg/ha, but comparable with the yield obtained from using 20t/ha (615kg/ha). The application of 10t/ha of CRH had yields (404.8 kg/ha) lower than the unapplied plots (560.6kg/ha). As the level of CRH increased, the soils moisture content correspondingly increased both before and after irrigation. The moisture content before irrigation ranged from 2.58% to 5.17% and 11.02% to 14.88% after irrigation. Garlic. CRH rates of 9t/ha, 6t/ha, 3t/ha, and 0t/ha were tested for garlic production. These were broadcast on the soil after planting. Two irrigation at 10-day interval were followed at 30 days after planting (DAP) and two irrigation at 15-day interval until 75 DAP. The average soil moisture content ranged from 21.86% to 34.03%. Plots applied with 9t/ha of CRH had the highest soil moisture content prior to irrigation. The CRH helped conserved soil moisture by suppressing moisture evaporation. The use of 9t/ha of CRH in heavy soils consistently produced the tallest plants at 30 DAP, 45 DAP, and 75 DAP. Lesser percentage of small bulb size was observed from the CRH applied plots compared with those plots without CRH. Plots applied with 9t/ha CRH produced the highest yield (3.62t/ha) but comparable with the yield obtained from the plots applied with 6t/ha CRH (3.46t/ha) and 3t/ha (3.4t/ha). Plots without CRH had the lowest yield at 2.27t/ha. The water productivity in plots applied with 9t/ha CRH (1.35kg/cu m) was comparable with plots applied with 6t/ha and 3t/ha CRH at 1.29kg/cu m and 1.27kg/cu m, respectively. The project concluded that the use of 20t/ha of CRH in sandy soils for mungbean production and 3t/ha in heavy soil for garlic production were the optimum values for increased yield and water productivity. Financial analysis on the use of CRH in garlic production showed higher net income from the plots applied with CRH than those without CRH. Net income from using CRH ranged from P160,356/ha. Price of garlic was P60/kg and CRH, P0.90/kg. Plots without CRH had a net income of only P81,612/ha.