基于设施番茄生产效益的最佳灌水量和控释氯化钾用量组合

The optimum combination of controlled-release potassium chloride and irrigation for efficient greenhouse tomato production

【目的】水、肥是影响作物生产效益的两个重要因素,过量施肥是导致设施栽培土壤盐渍危害的主要原因。为获得番茄优质高产并降低钾肥投入量,我们探究了灌水与控释氯化钾的适宜用量组合。【方法】盆栽试验在设施大棚内进行,供试番茄品种为‘罗拉’。设置常规灌溉(W_(100))下不施钾肥(CK)和施用全量普通氯化钾(K_(2)O 0.95 g/kg,CF)2个对照;设置3个控释氯化钾水平,分别为常规K_(2)O施用量的100%(K_(100))、80%(K_(80),K_(2)O 0.76 g/kg)和60%(K_(60),K_(2)O 0.57 g/kg);设置3个灌水梯度,分别为田间持水量的90%~100%(W_(100))、72%~80%(W_(80))、54%~60%(W_(60)),共11个处理。在番茄主要生育期,测定了叶片光合效率和土壤pH、电导率(EC)值,调查了果实产量和品质。【结果】K_(80)处理的平均果实产量和水分利用效率显著高于K_(100)处理,K_(100)处理又显著高于K_(60)处理,且K_(80)较K_(100)和K_(60)处理的总吸钾量(植株和果实)提高了3.4%~7.8%,Vc含量增加了3.4%~3.9%,可溶性糖含量增加了2.2%~6.5%,可溶性固形物含量增加了3.5%~7.4%,净光合速率提高了4.3%~10.9%,气孔导度提高了6.5%~11.9%,蒸腾速率提高了3.6%~9.5%。W_(80)处理的平均产量较W_(100)和W_(60)处理显著增加9.8%~16.0%,钾肥利用效率提高了6.3~7.1个百分点,V c含量增加了6.8%~24.0%,可溶性糖含量增加了5.6%~8.8%,可溶性固形物含量增加了6.6%~9.2%,净光合速率提高了4.1%~10.3%,蒸腾速率提高了8.4%~16.6%,开花期、果实膨大期和成熟期的SPAD值分别增加了4.8%~12.0%、1.7%~9.4%和4.6%~14.5%,土壤pH提高了0.9%~2.1%,电导率下降了4.9%~8.2%。在9个水钾组合处理中,除K_(60)W_(100)和K_(60)W_(60)处理外的其他处理均获得了显著高于CK和CF的产量及水分利用效率,K_(80)W_(80)处理的产量、品质最高,水、钾利用效率也处于较高水平。【结论】灌水与控释氯化钾对提高番茄的产量品质和光合效率有显著的正交互作用,二者最佳的用量组合是减少灌溉量至72%~80%(W_(80))与减少20%的K_(2)O投入量并一次性基施,可提升番茄的光合效率,同时提高了土壤pH,降低了EC值,因而增加了番茄产量、品质,提高了水分和钾肥利用效率。

【Objectives】Fertilizer and water are the two important inputs for efficient crop production.Excessive fertilization is the main cause of soil salinization under facility cultivation.Here,we studied the potential of reducing potassium input using controlled-release potassium chloride fertilizer(CR-KCl)and a matching irrigation level.【Methods】A pot experiment was conducted in a greenhouse,using tomato cultivar‘Luo la’as test material.The two controls were no K application and conventional KCl(K_(2)O 0.95 g/kg)application under 90%-100%field capacity irrigation(CK,CF).The nine fertilizer and water combination treatments comprised three CR-KCl dosages[100%(K_(100)),80%(K_(80)),and 60%(K_(60))of CF)]and three irrigation levels[90%-100%(W_(100)),72%-80%(W_(80)),and 54%-60%(W_(60))of the field capacity].Leaf photosynthetic efficiency,soil pH,and soil EC were measured during the main growth stages of tomato.Also,the tomato yield and quality were investigated.【Results】The average fruit yield and water efficiency of tomato were K_(80)>K_(100)>K_(60).Compared with K_(100) and K_(60),K_(80)(P<0.05)increased tomato K uptake(plant and fruit)by 3.4%-7.8%,Vc by 3.4%-3.9%,soluble sugar content by 2.2%-6.5%,soluble solid by 3.5%-7.4%,enhanced the net photosynthetic rate by 4.3%-10.9%,stomatal conductance by 6.5%-11.9%,and transpiration rate by 3.6%-9.5%.Compared with W_(100) and W_(60),W_(80)(P<0.05)increased tomato yield by 9.8%-16.0%,K utilization efficiency by 6.3-7.1 percentage points,Vc by 6.8%-24.0%,soluble sugar by 5.6%-8.8%,soluble solid by 6.6%-9.2%,net photosynthetic rate by 4.1%-10.3%,transpiration rate by 8.4%-16.6%,SPAD value at flowering,fruit enlargement,and ripening stage by 4.8%-12.0%,1.7%-9.4%and 4.6%-14.5%,soil pH value by 0.9%-2.1%,and EC value decreased by 4.9%-8.2%.Among the 9 CR-KCl and irrigation combinations,except for K_(60)W_(100) and K_(60)W_(60),tomato fruit yield and water use efficiency were(P<0.05)higher in other treatments than CK and CF,K_(80)W_(80) achieved the highest yield and quality,and K and water use efficiencies were also high.【Conclusions】CR-KCl and irrigation affected tomato yield,quality,and photosynthetic efficiency.The optimum combination of CR-KCl and irrigation was 20%less K_(2)O dosage in the one-time basal application and irrigation level of 72%-80%field water capacity(W_(80)).This combination had the highest fruit yield and quality,improved soil pH,reduced EC value,and had high fertilizer and water use efficiency.