The seeds of crops were sown manually on May 7, 2009.
Adjacent subplots were separated by a 0.5-m ridge, and the
main plots were separated by a 2-m ridge. All plots were given
100 kg P2O5 ha1 as the triple superphosphate, and 50 kg
potassium sulfate ha1 together with half of the N fertilizer
(25 kg ha1) were uniformly broadcasted and plowed 15 cm
into the soil before sowing. The other half of the N fertilizer
was applied with irrigation approximately 30 DAP. During
the growth period, all plots were weeded manually. No serious
incidents of insects or diseases were observed, and no pesticide
or fungicide was applied.