Field experiment of soil management was established to study effects of growing mungbean as green manure (non-growing and grow

Effects of Land Preparation and Fertilizer as Soil management on Corn Yield Grown on Lopburi Soil Series.¹

Satit Areerak²

1. M.Sc. thesis, Kasetsart University, Bangkok, 10900. Thailand.

2. Nakhon Sawan Field Crops Research Centre, Tak-Fa, Nakhon Sawan, 60190. Thailand.

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Field experiment of soil management was established to study effects of growing mungbean as green manure (non-growing and growing mungbean as green manure), land preparation practices (no-tillage, conventional tillage, and deep tillage) and rates of chemical fertilizer (0-0-0, 5-0-0, 5-5-0 + 5-0-0 top dressing, 10-5-0 and 10-10-0 kg/rai) on soil properties, growth, yield, nutrients composition, and nutrients uptake of corn at Nakhon Sawan Field Crops Research Centre during 1987 growing season by using split-split plot design, with green manure as main-plot, land preparation as subplot and fertilization as sub-subplot.

Bulk density of the soil trended to decrease when growing mungbean as green manure before growing corn, but was not different among land preparation practices. Soil moisture content was increased when growing mungbean as green manure. The soil moisture content from deep tillage practice was the highest when compared to no-tillage and conventional tillage practices.

Corn growth rate from growing mungbean as green manure was significantly higher than that from no mungbean as green manure but they were difference among land preparation practices and rates of chemical fertilizer. Corn yield were significantly increased from 519 to 653 kg/rai when growing mungbean as green manure before growing corn, but yields were not affected by three different land preparation practices.

Corn yields were significantly increased when chemical fertilizers were applied. The chemical fertilizer rate of 5-5-0 + 5-0-0 top dressing gave the highest corn yield (621 kg/rai) while the rate of 10-10-0 gave the corn yield of 619 kg/rai. The rate (0-0-0) gave the lowest corn yield (527 kg/rai).

Nitrogen concentration in grain and stover were increased when mungbean was used as green manure.

Phosphorus concentration in stover was decreased but phosphorus concentration in grain was not different when mungbean was used as green manure. Potassium concentration in grain and stover were not effected by green manure. Nitrogen, phosphorus and potassium concentration were not significantly different among land preparation practices and chemical fertilizer rates.

Nitrogen uptake in corn was significantly increased when used mungbean as green manure, but phosphorus and potassium uptake in corn were not significantly differences. Nitrogen, phosphorus and potassium uptake in corn were not significantly difference among land preparation practices and chemical fertilizer rates.