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三峡库区紫色土约30%为酸性.土壤酸性赋予其与中性或碱性土壤不同的理化性质,进而导致土壤磷淋溶特征不同.为研究三峡库区酸性紫色土磷淋溶特征,本研究利用温室盆栽试验,设置了不同过磷酸钙用量(0,1.006,2.515,4.527,6.036g/盆)对酸性紫色土磷淋溶及玉米生物量、磷素吸收和利用的影响.结果表明:酸性紫色土(旱地)自身磷淋溶量较高,达164.6μg/盆,施入少量磷肥,各形态磷淋溶量显著增加,但当施磷量达到2.515g/盆(即农户普遍磷用量87kg/km2)以上时,磷淋溶量不再随施磷量的增加而增加,呈下降—升高—稳定趋势.土壤总磷淋溶峰出现在玉米拔节期和灌浆期;玉米7~8叶期是溶解性磷和正磷酸盐淋溶高峰期,之后随玉米的生长总体上呈下降趋势.颗粒态磷是土壤磷淋溶的主要形态;溶解性有机磷是溶解态磷淋溶最主要的形态.本研究中,当地农民普遍施磷水平I2(2.515g/盆)为磷淋溶最低处理,但磷肥利用率仍然很低,仅为14.7%.
About 30% of the purple soil in the Three Gorges Reservoir Area is acidic, and soil acidity gives different physico-chemical properties to neutral or alkaline soil, leading to different phosphorus leaching characteristics.To study the leaching characteristics of acid purple soil in the Three Gorges Reservoir area, The greenhouse pot experiment was conducted to study the effects of different amounts of superphosphate (0, 1.006, 2.515, 4.527 and 6.036 g / pot) on the leaching of phosphorus and the biomass and phosphorus uptake and utilization of maize biomass.The results showed that: The leaching amount of autophosphorus in acidic purple soil (upland) was 164.6μg / pot with a small amount of phosphate fertilizer, and the phosphorus leaching increased significantly. However, when the phosphorus application reached 2.515g / pot 87kg / km2), the leaching amount of phosphorus no longer increased along with the increase of phosphorus application amount, but showed the tendency of descending-increasing-stabilizing. The leaching peak of total phosphorus in soil appeared at jointing stage and filling stage of corn; Leaf stage is the peak of soluble phosphate and orthophosphate leaching, followed by a downward trend with the growth of maize.Particle phosphorus is the main form of soil phosphorus leaching; Soluble organic phosphorus is the most important phosphorus leaching In this study, the local farmers generally phosphorus level I2 (2.515g / pot) for the phosphorus Lin Soluble minimum treatment, but phosphate fertilizer utilization rate is still low, only 14.7%.