Using green manure for sorghum grown on loamy sand soil

 

Boonoom Klawyotha

Kasetsart University, Bangkok 10900

 

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Green manure crops (Crotalaria sp. and Sesbania sp.) were grown on loamy sand soil in June 1991 at Mukdahan Field Crops Experiment Station, Mukdahan province, where soil type is classified as Korat soil.  At 60 days of age before incorporating into the soil, crotalaria was significantly superior to sesbania in plant height (199 vs. 153 cm) and total fresh weight (3,400 vs. 1,240 kg/rai) and dry weight (857 vs. 364 kg/rai).  According to soil analyses for pH and organic matter content at 25 days after the green manure crop incorporation, there were slight increases or changes in pH and organic matter (4.7 to 4.9% and 0.50 to 0.67%, respectively in crotalaria). In sesbania, pH increased from 4.7 to 4.8% and organic matter increased from 0.50 to 0.78%). 

Sorghum was planted after the green manure crop incorporation; plant performances as well as height, 1,000-seed weight and grain weight of sorghum followed crotalaria were higher than those followed sesbania and those without green manure.  Mean grain yield of sorghum followed crotalaria (462 kg/rai) was higher than that followed sesbania (360 kg/rai) and that without green manure (216 kg/rai).  Sorghum followed crotalaria and fertilized with 4 kg of nitrogen/rai yielded comparable to that fertilized with 8 kg of nitrogen/rai.

 

 

 

 

Greenmanure