ผลการใช้กากเมล็ดสบู่ดำเป็นปุ๋ยอินทรีย์ที่มีต่อผลผลิตข้าวโพดหวาน

Abstract

Objective of this experiment was to use seed cake of Jatropha as the organic fertilizer for sweet corn production. Property of fresh seed cake of Jatropha was pH 6.6, EC 1.77 dS/m, total N 3.55 percent, total P2O5 1.47 percent, total K2O 1.39 percent, total Ca 0.68 percent, and total Mg 0.64 percent. Plot research was conducted at the National Corn and Sorghum Research Center. The experiment was repeated in 6 crop seasons in 2007-2009. Randomized complete block design was laid out, with four replications and six treatments. The six treatments were chemical fertilizer application at the recommendation, cow manure application (2500 kg/rai), Jatropha seed cake application (620, 800, and 1000 kg/rai), and no fertilizer application. The combined analysis of the six crop seasons revealed that seed cake of Jatropha at the rate of 1000 kg/rai gave total green ear yield of sweet corn similar to chemical fertilizer but chemical fertilizer gave higher amount of grade 1 size of the green ear yield. There was no toxic residual of phorbol esters found in the fresh sweet corn. It was also found that the organic matter in the soil was improved by application of Jatropha seed cake and cow manure, compared to that of chemical fertilizer application and no fertilizer application.