EFFECTS OF CATTLE MANURE, GREEN MANURE AND CHEMICAL FERTILIZER 13-13-21 (NPK) ON GROWTH AND KERNEL YIELD OF MAIZE (<I>Zea mays</I> L.) GROWN ON YASOTHON SOIL

Abstract

The experiment was carried out during July-September 1991 on Yasothon soil at the Experimental Farm. Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand to investigate the effect of organic manure, green manure and chemical fertilizer 13-13-21 (NPK) upon growth and kernel seed yields of maize Rungsit 1. variety. The treatments used were the same as those carried out by Suksri et al. (1991) but chemical fertilizer 13-13-21 (NPK) was used instead of chemical fertilizer 15-15-15 (NPK).

The results showed that total dry weights at the initial sample were similar for all treated plants yet at the second sampling period, total dry weights of the crop plants increased more rapidly with time in all treated plants except the two treatments i.e. the cattle manure alone (T₆) and the control treatment (T₁). Leaf areas were highest with green manure plus 25 kg/rai chemical fertilizer 13-13-21 NPK (T₃) and the chemical fertilizer 13-13-21 at the rate of 30 kg/rai (T₄). An increase in the amount of chemical fertilizer did not increase leaf areas and leaf dry weights of the maize plants. However, cob dry weights were significantly highest with the chemical fertilizer 13-13-21 at the rate of 60 kg/ rai  followed by the green manure plus 25 kg/rai 13-13-21 (T₃) and also the chemical fertilizer at the rate of 30 kg/rai, the rest were similar. At the final harvest, kernel yields were similar in all treated plants. Nevertheless, it was evidently shown that the applications of either green manure or cattle manure together with chemical fertilizer 13-13-21 at the rate of 25 kg/rai gave the highest kernel yields. The maize kernel yields were ranging from 318, 329, 379, 414, 433, 452 and 457 kg/rai for T₁, T₇ ,T₆ T₃, T₄, T₅, and  T₂ respectively. Growth and yields of maize was affected most by drought.