栽培方式与钾互作对食用向日葵产量、品质和钾素利用率的影响

  【目的】  研究阴山北麓旱作区不同栽培方式下钾肥施用量对食用向日葵钾肥效应、产量性状、钾素吸收利用、油分品质和土壤–植物系统钾素平衡的影响，为向日葵上钾肥的科学施用提供理论依据。  【方法】  2014—2016年在内蒙古阴山北麓旱作区以食用向日葵 (3638C) 为研究对象，采用田间定位试验方法，裂区设计，主因素为3种栽培方式:平作雨养种植 (R)、全覆膜垄膜沟植集雨 (RC) 和全覆膜垄膜沟植滴灌 (I)。副因素为4个施钾水平:0、48、84和120 kg/hm2，表示为K₀、K₄₈、K₈₄和K₁₂₀。研究水钾互作对食用向日葵籽粒产量、产量性状、钾素吸收、钾肥利用效率、油分品质及土壤钾素平衡等的影响。  【结果】  栽培方式是影响向日葵籽实产量、花盘直径、千粒重、出仁率、钾素吸收量和钾肥利用效率的主要因素，3个栽培处理表现为全覆膜垄膜沟植滴灌 (I) > 全覆膜垄膜沟植集雨 (RC) > 平作雨养种植 (R)。全覆膜垄膜沟植滴灌 (I) 条件下，随着施钾量的增加，产量、花盘直径、千粒重、出仁率和钾素吸收量也增加，推荐施钾量 (K₂O) 为120 kg/hm2时，产量、花盘直径、千粒重、出仁率和钾素吸收量最高；全覆膜垄膜沟植集雨 (RC) 条件下，推荐施钾量 (K₂O) 为84 kg/hm2时，产量最高；平作雨养 (R) 条件下各施钾处理之间的产量、花盘直径、千粒重差异不显著。钾肥利用率和农学效率随着施钾量的增加而降低。栽培方式对籽实含油率影响较小，水分条件的改善有利于亚油酸含量的增加。随着钾肥用量的增加向日葵籽实的含油率也相应增加，主要是增加了亚油酸的含量。全覆膜垄膜沟植滴灌 (I) 条件下，推荐施钾 (K₂O) 量为120 kg/hm2时，土壤–植物系统的钾素基本平衡；全覆膜垄膜沟植集雨 (RC) 条件下，推荐施钾 (K₂O) 量为84 kg/hm2时，土壤–植物系统的钾素基本平衡；平作雨养 (R) 条件下，推荐施钾 (K₂O) 量为48 kg/hm2时，土壤–植物系统的钾素基本平衡。  【结论】  在内蒙古阴山北麓旱作区，全覆膜垄膜沟植滴灌 (I)、全覆膜垄膜沟植集雨 (RC) 和平作雨养种植 (R) 的推荐施钾 (K₂O) 量分别以120、84、48 kg/hm2为宜，此时，土壤–植物系统的钾素基本平衡。增施钾肥可增加向日葵籽实的含油率，主要是增加了籽实的亚油酸含量。

Effects of cultivation methods and potash fertilizer on seed yield,qualityand potassium use efficiency of sunflower

  【Objectives】  Effects of potassium (K) application levels and different cultivation methods on seed yield and quality, and K fertilizer efficiency of sunflower were studied. The aim was to identify efficient and sustainable K nutrient management.  【Methods】  The field experiment was conducted in north Yinshan area, Inner Mongolia, China, over a 2-year period (2014?2016). Sunflower of 3638C for comsuming seeds was used as the test material. The experimental plots were mulched with plastic film. The sunflower was subjected to three different cultivation conditions planting in flat field without irrigation (R), planting in furrow between ridges without drip irrigation (RC), and planting in furrow between ridges with drip irrigation (I)] and four K levels (0, 48, 84 and 120 kg/hm2). At harvest, the seed yield and yield components, the K contents in stalk, eeds, and soil were measured.  【Results】  Water supply, which is affected by the cultivation method, was the main factor that affected sunflower seed yield and yield traits. The disc diameter, 1000-seed weight, seed kernel ratio, K uptake, potash fertilizer efficiency were all in order of I>RC>R. The seed yield, yield traits and K uptake increased with increase in K rate under I treatment, but did not change under R treatment. The utilization rate and agronomic efficiency of potash fertilizer decreased with increase in K rate in all the three cultivation conditions. K rate had significant effect on the seed oil content, especially the linoleic acid content. The basic K balance of soil under I, RC and R conditions were K₂O rate of 120 kg/hm2, 84 kg/hm2 and 48 kg/hm2, respectively.  【Conclusions】  Our results showed that furrow planting of sunflower is preferred to flat planting, especially under irrigation. For high seed yield, quality and potash fertilizer efficiency, and balanced soil K in north Yinshan area, Inner Mongolia, about 120, 84 and 48 kg/hm2 of K₂O should be applied under furrow planting with irrigation, furrow planting without irrigation, and flat planting under rainfed condition, respectively.