枸溶性钾肥的水稻肥效

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%(P0.05)。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。

The effect of citrate soluble potassium fertilizers on rice growth

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 K2O 150 mg/kg], and different application rates (0. 5K2, K2, 1. 5K2 and 2K2 at rates of K2O 75, 150, 225 and 300 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 fertil-izer, 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. 4 mg/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% and 21. 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; citrate-soluble potassium fertilizer (K2) had same effect at 2-fold K application rate as compared with K4 and K3.