黄腐酸对蒜套棉制度下棉花产量品质及土壤性状的影响

为明确黄腐酸在蒜套棉生产中棉花上的应用效果,实现棉花高产优质高效施肥,进行两季大田试验,试验设不施肥(CK)、常规施肥(BF)、常规施肥配施低、中、高量黄腐酸微生物菌剂(FA20、FA30、FA40)、常规施肥配施黄腐酸叶面肥(BFL50)、常规施肥配施低量黄腐酸微生物菌剂及黄腐酸叶面肥(FA20L50)共7个处理,研究不同黄腐酸肥料与常规肥料配施对蒜套棉制度下棉花产量、纤维品质及土壤养分的影响。结果表明:(1)与常规施肥相比,皮棉产量随着黄腐酸微生物菌剂用量的增加而增大,FA30、FA40皮棉产量较BF显著增产12.07%和22.41%,在苗期和盛花期显著提高土壤硝态氮、铵态氮和速效钾含量,FA40还提高了土壤有效磷含量。(2)常规施肥配施黄腐酸叶面肥处理皮棉产量较常规施肥处理平均增产7.19%,在盛花期叶片SPAD提高7.78%,并显著提高了气孔导度和净光合速率,降低胞间CO2浓度。(3)FA20L50较FA20和BFL50皮棉产量提高7.68%~27.51%,同时提高了纤维长度、整齐度指数和断裂比强度,并提高了土壤硝态氮、铵态氮、有效磷和速效钾含量,土壤磷酸酶活性显著高于其他各处理。FA20L50处理的棉花茎和叶中氮、磷和钾总量与FA40差异不显著,但显著高于其他各处理;在铃壳中的养分总量较其他各处理提高8.96%~47.35%,净光合速率显著高于未施用黄腐酸叶面肥的处理。综上所述,常规肥料配施300kg/hm^2黄腐酸微生物菌剂与750mL/hm^2黄腐酸叶面肥处理田间施用效果最佳,能够提高棉花各生育期土壤速效养分供应,有利于养分在生殖器官中的积累,促进棉花叶片的净光合速率,提高棉花产量及品质。

Effect of Fulvic Acid on Cotton Growth and Soil Chemical Properties in a Garlic-cotton Intercropping System

In order to clarify the effect of fulvic acid application on cotton in garlic-cotton intercropping production and realize high-yield, high-quality and high-efficiency fertilization of cotton, a two-season field experiment was conducted. The experiment consisted of no fertilization (CK), conventional fertilization (BF), conventional fertilization combined with low, medium and high rates of fulvic acid microbial agents (FA20, FA30, FA40), conventional fertilization combined with fulvic acid foliar fertilizer (BFL50), conventional fertilization combined with low amount of fulvic acid microbial agent and fulvic acid foliar fertilizer (FA20L50). The effects of different fulvic acid fertilizers combined with conventional fertilizers on yield, fiber quality and soil nutrients of cotton-garlic intercropping were studied. The results showed:(1) Compared with conventional fertilization, the yield of cotton lint increased with the increase of the fulvic acid microbial agents application rates. The average lint yield in FA30 and FA40 treatments increased significantly by 12.07% and 22.41% respectively in comparison with BF treatment. Meanwhile, FA30 and FA40 treatments significantly increased soil nitrate nitrogen, ammonium nitrogen and available potassium contents during seedling and full bloom, FA40 also increased soil available phosphorus contents. (2) The cotton lint yield of conventional fertilization combined with fulvic acid foliar fertilizer increased by 7.19% on average compared with conventional fertilization, and the SPAD of leaves increased by 7.78% during flowering stage, which significantly increased stomatal conductance and net photosynthetic rate, and decreased intercellular CO₂ concentration. (3) Compared with FA20 and BFL50, FA20L50 increased lint yield by 7.68%~27.51%, significantly increased fiber length, evenness index and breaking strength. Moreover, FA20L50 increased soil ammonium, nitrate, available phosphorus and available potassium contents. Soil phosphatase activity in FA20L50 was significantly higher than other treatments. The total amounts of nitrogen, phosphorus and potassium in cotton stems and leaves in FA20L50 treatment were significantly higher than other treatments, besides FA40 treatment. FA20L50 increased the total nutrient contents by 8.96%~47.35% in the bell shell in comparison with other treatments, and significantly improved the net photosynthetic rate compared with treatments without fulvic acid foliar fertilizer. In conclusion, conventional fertilizer combined with 300 kg/hm² fulvic acid microbial agent and 750 mL/hm² fulvic acid foliar fertilizer had the best application effect, which could improve the available nutrient supply of soil at all growth stages of cotton and facilitate the accumulation of nutrients in reproductive organs, thus promote the net photosynthetic rate of cotton leaves and improve the yield and quality of cotton.