秸秆腐熟剂处理稻草还田对莴苣减量化施肥的效果初探

Preliminary Study on Reduction of Lettuce Fertilization Using a Straw Decomposition Agent

在测土配方施肥的基础上，推广稻草还田腐熟技术。结合机收，采用秸秆腐熟剂使稻草就地还田，开展莴苣减量化施肥的最佳效果研究。结果表明：与无稻草还田相比，应用秸秆腐熟剂处理稻草还田腐熟后，配施适量化肥，莴苣产量可增加833.40～1633.35 kg · hm-2，增长1.42％～2.79％，株高增高、茎粗增粗；土壤理化性状改善，当季土壤有机质含量增加0.2～0.5 g.kg -1，提高0.65％～1.61％。其中，处理3（稻草还田＋腐熟剂＋氮磷肥各减10％，钾肥减20％）产量最高，为60000.30 kg · hm -2，比处理1增长2.79％。处理2（稻草还田＋腐熟剂＋氮磷肥各减10％，钾肥减10％）土壤有机质含量最高，为31.5 g · kg -1，提高1.61％；有效磷含量最高，为98.3 mg · kg -1，增长12.6％。处理3碱解氮含量最高，为120 mg · kg -1，增长3.45％。本试验条件下，秸秆还田量4500 kg · hm -2，氮、磷肥用量减少10％，钾肥用量减少10％～20％处理为宜。

Decomposed rice straws were applied on a lettuce field in an attempt to reduce fertilization .Along with the mechanical rice harvesting ,a decomposition agent was added to the straws to optimize the application .The results showed that ,in comparison with the control ,the treatments increased the lettuce production by 833.40 -1 633.35 kg · hm -2 ,or 1.42% -2.79% .The lettuce plant height and stem girth increased ,and the soil nutrient profile improved .The seasonal soil organic matter content increased by 0.2-0.5 g · kg -1 （0.65% -1.61% ） with a reduction on the amount of fertilizer used .The lettuce yield under Treatment 3 was the highest among all with 60 000.30 kg · hm-2 ,an increase of 2.79% over the control . The organic matter content of the lettuce under Treatment 2 was the highest （i .e .,31.5 g · kg -1 ） ,and the available P was the highest as well （98.3 mg · kg-1 ） among all .And ,the lettuce treated by Treatment 3 contained the most alkali-hydrolyzable nitrogen （i .e .,120 mg · kg -1 ） .As a result ,it was concluded that , with the straw decomposition agent ,the optimal addition rate of dry straws to the field was 4 500 kg per hectare ,while a 10% reduction on nitrogen and phosphate and 10% to 20%on potash fertilization was achieved .