冀中地区桃树优质高产的叶片氮磷钾临界值范围及化肥投入量

目的]研究叶片养分含量与产量、品质的关系,并依据该关系确定冀中地区桃树优质高产的叶片氮磷钾临界值范围,及实现该目标所需的化肥投入量与土壤养分保证量.方法]在冀中地区选取60个小型桃园进行了连续3年的跟踪监测.于盛花期后60天采集桃树叶样,测定氮磷钾含量.收获后,调查果实产量、单果重和可溶性固形物含量(SSC),将各...

Leaf NPK concentration requisite and chemical fertilizer inputs for high yield and quality of peach production in central Hebei Province

  【Objectives】  We surveyed the critical leaf NPK concentration of high quality and high yield peach, the required chemical fertilizer inputs, and soil available nutrient content to achieve peach’s target yield and quality in central Hebei Province.  【Methods】  We selected 60 small peach orchards in central Hebei Province, and leaf samples were collected at 60 days after the full bloom stage to analyze NPK contents. The surveys were conducted for three consecutive years. The three production objectives (yield, single fruit weight, and soluble solid content (SSC)) were investigated at harvest, and the indexes were divided into four grades. The single factor analysis of variance and boundary line analysis were used to test the relationship between leaf nutrient content, chemical fertilizer input, and soil available nutrient content.   【Results】  The observed leaf nutrient content variation gradually decreased with increasing yield and quality of peach, and the contents for the highest grade were moderate. The total N, P, and K boundary values for the three objectives were distributed in typical parabolic shapes. Based on the boundary line equations, the critical ranges of total leaf N, P, and K were 3.33%–4.12%, 0.16%–0.29% , and 1.54%–2.50% for the high-yield target (>45 t/hm2), 3.05%–4.61%, 0.13%–0.35% and 1.45%–2.57% for large single fruit weight (>350 g), 3.30%–4.09%, 0.17%–0.32%, and 1.59%–2.64% for sweetness (SSC>15%), respectively. The comprehensive leaf N, P, and K ranges that meet high yield and quality were 3.33%–4.09%, 0.17%–0.29%, and 1.59%–2.50%, respectively. The critical leaf N, P, and K values had a significant linear boundary relationship with chemical N, P₂O₅ fertilizer input, and soil readily available K content. The inflection points for N and P₂O₅ fertilizer input were 210.2 kg/hm2 and 236.3 kg/hm2, and 110.2 mg/kg for soil readily available K content. The chemical fertilizers required to ensure leaves appropriate N, P and K nutrient content were 40.2–166.8 kg/hm2 for N, 11.3–161.3 kg/hm2 for P₂O₅, and 36.3–86.8 mg/kg for soil readily available K, respectively.   【Conclusions】  Considering fruit yield, individual fruit weight, and sweetness, the critical leaf N, P, and K at 60 days after the full bloom stage were 3.33%–4.09%, 0.17%–0.29%, and 1.59%–2.50%, respectively. The required fertilizer input to attain critical leaf NPK concentration were 40.2–166.8 kg/hm2 for N, 11.3–161.3 kg/hm2 for P₂O₅, and 36.3–86.8 mg/kg for soil readily available K content, respectively.