枸溶性钾肥的水稻肥效

The effect of citrate-soluble potassium fertilizers on rice growth

通过盆栽试验研究了5种钾肥[粉碎性钾矿粉（K1）、全部枸溶性钾肥（K2）、含25%水溶性钾的枸溶性钾肥（K3）、含50%水溶性钾的枸溶性钾肥（K4）和硫酸钾（K5）,施钾量均为K2O 150 mg/kg]及其施用量（0.5K2、K2、1.5K2和2K2,施钾量分别为K2O 75、150、225和300 mg/kg）和配施（0.5K2＋0.5K5）对水稻产量、钾素吸收量以及土壤速效钾含量的影响。研究结果表明,与不施钾相比,施钾肥处理（除K1外）均显著提高水稻产量、钾素吸收量以及土壤速效钾含量。在相同施钾量下,随着肥料水溶性钾比例的增加,水稻产量、钾素吸收量以及土壤速效钾含量表现为先上升后下降的趋势,其中水稻产量、钾素吸收量以及土壤速效钾含量以K4（分别为240.90 g/盆、2.60 g/盆、75.4 mg/kg）和K3（分别为234.86 g/盆、2.24 g/盆、73.9 mg/kg）处理最高。与水溶性钾肥（K5）处理相比,K4和K3处理均显著提高了水稻产量、钾素吸收量和土壤速效钾含量,分别提高了9.35%和6.61%、40.43%和21.26%、22.01%和19.58%（P〈0.05）。水稻产量、钾素吸收量及土壤速效钾含量随同一种枸溶性钾肥（K2）施用量的增加而增加,以2K2最高。综合结果表明,在相同施钾量下,含25%~50%水溶性钾的枸溶性钾肥（K4和K3）对水稻的增产效果最佳,而全部枸溶性钾肥在2倍施钾量下可获得相同增产效果。

A pot experiment was conducted to evaluate the effects of 5 different potassium（ K） fertilizers [potassium mineral（ K1）,citrate-soluble potassium fertilizer（ K2）,citrate-soluble potassium fertilizer containing 25% water-soluble potassium（ K3）,citrate-soluble potassium fertilizer containing 50% water-soluble potassium（ K4） and potassium sulphate（ K5） at rate of K2 O 150 mg / kg],and different application rates（ 0. 5K2,K2,1. 5K2 and 2K2 at rates of K2 O 75,150,225 and300 mg / kg,respectively） and combined application（ 0. 5K2 ＋ 0. 5K5） on rice biomass, K uptake and soil available K（ SAK） concentration. The results indicated that K application significantly increased rice biomass,K uptake and SAK except for K1 as compared with no K application treatment. Under same K application rate, rice biomass, K uptake and SAK markedly increased and then decreased with water-soluble potassium concentration increasing in citrate-soluble potassium fertilizer,and the highest values in rice biomass,K uptake and SAK were occurred in K4（ 240. 90 g / pot,2. 60 g / pot and 75. 4mg / kg） and K3（ 234. 86 g / pot,2. 24 g / pot and 73. 9 mg / kg,respectively） treatments. Compared with K5 treatment,K4 and K3 treatments both significantly increased rice biomass, K uptake and SAK by 9. 35% and 6. 61%,40. 43% and21. 26%,22. 01% and 19. 58%,respectively. Rice biomass,K uptake and SAK significantly increased with K2 application rate increasing and the highest values were observed in 2K2 treatment. The results demonstrated that citrate-soluble potassium fertilizer containing 25% ~ 50% water-soluble potassium（ K4 and K3） had the best effect in increasing rice growth; citratesoluble potassium fertilizer（ K2） had same effect at 2-fold K application rate as compared with K4 and K3.