การใช้ปุ๋ยเคมีร่วมกับปุ๋ยอินทรีย์เพื่อลดความเสี่ยงในการผลิตข้าว

Abstract

Twenty one experiments were conducted during 2004-2008 at two locations in Ubon Ratchathani (Ban Donchi and Ban Khem) and two locations in Surin (Ban Nonkan and Surin Rice Research Center) to compare effects of chemical and organic fertilizer in single and combine applications. Each location had randomized complete block design with three replications of 10 treatments ( 3-4-4,6-4-4 kg of N-P2O5-K2O/rai, 1,000 kg/rai of 4 organic fertilizers which were rice straw compost (RSC1000), farmyard manure (FYM1000), green manure (GM1000), rice husk (RH1000), 500 kg/rai of each kind of organic fertilizer applied with N at the rate of 3 kg/rai: RSC500+3N, FYM500+3N, GM500+3N, RH500+3N). KDML105 rice variety was transplanted with 20*20 cm spacing (except 25*25 cm at SRNRRC). Rice grain yield obtained with 3-4-4 and 6-4-4 kg of N-P2O5-K2O/rai were not different from 1,000 kg/rai of RSC, GM and RH, correspond to rice yield of 379, 394,393, 390, 370 kg/rai respectively. Only the FYM1000 gave grain yield of 427 kg/rai higher than those of single application treatments. The greatest fertilizer response was FYM500+3N and GM500+3N which gave 431 and 422 kg/rai respectively. Although soil chemical properties were not improved by the application of chemical and organic fertilizer with an average over 4 locations of 5.0 soil pH, 0.6 percent organic mater, 5.1 mg/kg soil available P and 10 mg/kg soil exchangeable K. However, application of chemical with organic fertilizer especially FYM and GM was necessary in unfertile sandy soil.