Itoshima

Harvest area

Yield is fundamental data in rice production when farmers evaluate and improve their production management. We proposed a low-cost measurement method for brown rice yield that is expected to be popularized in actual production fields. In the proposed method, we used brown rice weight measured at country elevator (C.E.) for each shipment and area harvested for each shipment, in order to measure brown rice yield for each shipment. The harvest area for each shipment was measured based on the moving track of combine harvester during harvest recorded by a low-price GPS logger. In this study, measurement accuracy of harvest area for each shipment was evaluated through the harvest surveies for 2 farmers (farmers A and B) in the city of Itoshima, Fukuoka prefecture. In addition, brown rice yield for each shipment was calculated by relating harvest area for each shipment with brown rice weight measured at C.E, and the yield variability among shipments was clarified. Measurement errors in harvest area for each shipment were less than 5% in the 28 shipments out of 31 shippments, i.e., 90 % of total shipments. Further, ranges and modes in brown rice yield for each shipment were 360-440 kg/10a and 380-400 kg/10a for farmer A, and 380-480 kg/10a and 340-460 kg/10a for farmer B. Namely, both variability and mode of brown rice yield were larger in farmer B. These results indicated that farmers can understand brown rice yield quantitatively, which has been recognized based on sense of individual farmers, by installing a low-price GPS logger in a combine harverster.

Contemporary