珠江三角洲粘土稻田早稻前期生长缓慢,分蘖迟的现象,群众称之谓“慢发”。禾苗慢发是影响产量的一个重要因素。为了解决这个问题,我们连续几年在顺德县伦教区对水稻在粘土稻田中的生长状况及生长环境进行了详细的观察和研究,发现造成早稻禾苗慢发的主要原因是土壤质地粘重,通透性差,土壤固磷能力强,有效磷含量偏低(详见本所1983年研究年报)。因此,秧苗含磷量较低,同时由于偏施氮素化肥,使磷氮比失调,秧苗质素较差,移 Early paddy rice paddy rice in the Pearl River Delta early growth slow, late tillering phenomenon, the masses said the “slow hair.” Slow seedling is an important factor affecting the yield. In order to solve this problem, we conducted a detailed observation and study on the growth status and growth environment of paddy rice in clay paddy fields in Lunjiao County, Shunde County for several years. We found that the main reason for slow hairiness of early rice seedlings is that the soil texture is sticky, Poor permeability, strong ability of fixing phosphorus in soil and low content of available phosphorus (for details, see our 1983 annual report). Therefore, the lower the phosphorus content of seedlings, at the same time due to the partial application of nitrogen fertilizers, so that the ratio of phosphorus to nitrogen, poor quality of seedlings, shift