生草覆盖下有机无机肥配施对苹果园土壤磷形态分布的影响

Effects of Combined Application of Organic and Inorganic Fertilizers on Soil Phosphorus Distribution in Apple Orchard Under Grass

依托13年长期定位试验采取裂区设计,主处理为行间生草覆盖和清耕,副处理为4个施肥处理,具体为不施肥(CK)、单施有机肥(M)、氮磷钾配施(NPK)、有机无机肥配施(MNPK),采用修正的Hedley磷分级方法浸提和测定各磷形态。结果表明:石灰性土壤0—20,20—40 cm土层各形态磷含量以盐酸态磷(D.HCl—P)和残留态磷(Residual—P)为主,水溶性磷(H 2 O—P)与碳酸氢钠无机磷(NaHCO 3—Pi)比例较低。经过13年生草覆盖和不同施肥处理,生草覆盖条件下有机无机肥配施提高土壤中无机磷的含量和占比,降低残留态磷的含量。比例在0—20,20—40 cm土层无机磷比例分别由68.5%和66.1%上升到75.8%和69.7%,残留态磷的比例由26.8%和27.0%下降到18.3%和23.5%。生草覆盖下有机无机肥配施可显著提高土壤有效磷和无机磷的含量以及H 2 O—P、NaHCO 3—Pi活性磷在土壤中的比例,生草覆盖结合有机无机肥配施能够增加土壤活性磷含量,保持高比例有效磷库,是提高当前苹果园磷肥利用率的重要措施,对保证该地区苹果高产、磷肥资源高效利用具有重要意义。

Based on 13 years of long-term positioning experiment,and the split plot design was adopted.The main treatment was the roots of grass coverage and clearing,The secondary treatment was four fertilizer treatments,including no fertilizer(CK),single application of organic fertilizer(M),combined application of nitrogen,phosphorus and potassium(NPK)and combined application of organic and inorganic fertilizer(MNPK).The modified Hedley phosphorus classification method was used for extraction and determination of various phosphorus forms.The results showed that the contents of various phosphorus forms in 0—20 cm and 20—40 cm layers of calcareous soil were mainly D.HCl—P and residue—P,and the ratio of water-soluble phosphorus(H 2 O—P)to inorganic phosphorus sources of sodium bicarbonate(NaHCO 3—Pi)was low.After 13 years of grass mulching and different fertilization treatments,the combined application of organic and inorganic fertilizers under grass mulching conditions increased the content and proportion of inorganic phosphorus in soil,and the content and proportion of residual phosphorus in 0—20 cm and 20—40 cm soil layers reduced from 68.5%and 66.1%to 75.8%and 69.7%,respectively,the proportion of residual phosphorus decreased from 26.8%and 27.0%to 18.3%and 23.5%,respectively.The combined application of organic and inorganic fertilizers under grass mulch could significantly increase the contents of available P and inorganic P in soil and the proportion of H 2 O—P and NaHCO 3—Pi active P in soil.The combined application of organic and inorganic fertilizers under grass mulch could increase the content of active P in soil and maintain a high proportion of available P pool,which was an important measure to improve the utilization rate of P fertilizer in apple orchard.It is very important to ensure the high yield of apple and the efficient utilization of phosphorus fertilizer resources in this area.