Productivity and seed quality of rice (Oryza sativa L.) cultivars grown under synthetic, organic fertilizer and biodynamic farming practices

A study was conducted at PhilRice Nueva Ecija (2005 WS) to compare the performance of rice varieties under, four pesticide-free production practices: 'synthetic' (or 'chemical' fertilizer), 'organic' (composted poultry manure), 'biodynamic' (biodynamic preparations, no,fertilizer) and 'control' (no fertilizer). The varieties, developed and/or maintained by the Philippine Rice Research Institute (PhilRice), were PSB Rc82, PSB Rc72H and Dinorado Gold. Parameters measured included yield and other agronomic traits, eating quality, germination of artificially aged seeds, soil quality, and costs and returns. Treatments were in factorial combination, laid out in split plot in Randomized Complete Block Design in three replications. Results showed that varieties differed from each other in many parameters, but the difference was more from Dinorado than from the other varieties. Crop performance also differed with production practices. Yield of Dinorado (tallest variety) was not assessed because of uneven stand due to extensive lodging. PSB Rc72H (a hybrid) had 8% higher grain yield than PSB Rc82 (a pure line). PSB Rc72H also had higher number of productive tillers, shoot biomass, 1000-.seed weight and harvest index. Grain yield of 'synthetic' was 14% higher than 'organic,' while that of 'biodynamic, ' which was third in rank, was 13% higher than control. In terms of seed resistance to accelerated aging, Dinorado tended to have better vigor or storability than the PSBs. 'Organic', followed by 'biodynamic' also were better than 'synthetic. '.Soil phosphorus increased after cropping but only with 'biodynamic' (20%) and 'organic' (18%). Root development was greatest for 'biodynamic' and 'organic. ' 'Organic' gave greater net profit (16%) and return on investment (30%) than 'synthetic: ' 'biodynamic' ranked next to 'organic. "Tungro, which affected Dinorado, was controlled by a 'biodynamic' preparation of horsetail (Equisetum arvense). The polished 7-month grains (cooked and uncooked) of the PSBs were more favored in eating quality than the Dinorado. 'Organic' ranked highest in most sensory parameters while 'synthetic' mostly ranked last among the four practices. Except in yield, 'organic' proved the best performer in the study, while 'biodynamic' presented good potential under a low-input system.