Studies on the Yield Rate, Nutrient Composition, and Simple Bulk Handling Methods to Maintain the Nutritional Value of Stored Rice Straw

Rice straws are available in large quantities during harvesting, but most are left without protection and treatment in the rice field. The poorly handled straws are underutilized as feed due to physical and microbial damage, nutrient loss, palatability, and digestibility. The research aimed to study (1) the availability and nutrient content of straws of different varieties and parts and (2) the beneficial effects of simple bulk handlings to maintain the nutritional values of stored rice straw. Fresh straw samples of three local rice cultivars were collected from 15 rice farmers. The varieties were Anak Daro (AD), Cisokan (CS) and Bujang Marantau (BM). The stem, leaf, and panicle straw parts were separately cut, weighed, dried, ground, and analyzed for crude nutrients. About 1.8 tons of fresh straw were used for the storage experiment. They were divided into three parts (@ 600 kg). Each part was stacked, rolled, wrapped in forty-eight bulk parties of 50 kg-size each, and then stored for 90 days at room temperature. Samples were taken on the days 0, 30, 60, and 90. Parameters measured were the percentage of the stem, leaf, and panicle, crude nutrient, fiber fraction, and digestibility of dry matter (DM) and organic matter (OM). Data on the field survey was statistically analyzed in a one-way, completely randomized design, while the storage data were analyzed in two-way variance analysis. The result shows that the mean straw yield was 66.5 and 242.9% of the whole plant and grain yield, respectively. The straw comprised 71.4, 20.5, and 8.1% stems, leaves, and panicles. BM cultivar had the lowest straw yield and DM content but the highest crude protein (CP). Panicles had the highest DM and CP content, followed by leaves and stems. There was no significant effect of bulk handling methods on the percentage of straw parts, CP and fiber fraction, and digestibility. The DM content of stacked and rolled straw increased while wrapping maintained the moisture content during the storage period. In conclusion, stems and panicles were found to be the most valuable straw parts, and the stored straw should be wrapped to keep nutrient and moisture content.