有机-无机配施对盐渍土壤水稻生长及养分利用的影响

针对滨海盐渍化土壤水稻种植过程中根系生长受盐碱胁迫,导致养分利用率低的问题。采用田间试验研究了有机肥与磷肥配施对滨海盐渍化土壤水稻不同生育期根系生长、水稻产量及养分利用率的影响。试验采用双因素设计,3个碳水平:(1)C0,无碳;(2)C1:低碳,450 kg/hm~2;(3)C2:高碳,900 kg/hm~2;3个磷水平:(1)P0:无磷;(2)P1:低磷,P_2O_5 64 kg/hm~2;(3)P2:高磷,P_2O_5 128 kg/hm~2。结果表明,在水稻成熟期,低碳低磷(T5)处理时根系总表面积显著高于高碳低磷(T7)和高碳高磷(T8)处理,分别增加25.2%和30.2%;低碳处理(T5、T6)时根系总体积显著高于高碳处理。T5处理时水稻产量、生物量显著高于其他处理,分别为10 245,9 550 kg/hm~2。结实率较高是低碳低磷(T5)处理水稻产量最高的原因。低碳低磷(T5)处理时糙米P积累量最高,显著高于T6、T7、T8处理,分别高出13.9%,27.8%,31.2%。T5处理的磷肥贡献率和农学效率显著高于其他施磷肥处理。磷肥偏生产力表现为低磷投入显著高于高磷投入。综上所述,与单独施用无机肥相比,有机肥与磷肥配施能够显著促进滨海盐渍化土壤水稻根系生长,提高水稻产量及磷肥农学效率,其中低碳低磷(T5,C 450 kg/hm~2+P_2O_5 64 kg/hm~2)处理最有利于盐渍化土壤水稻根系生长。

Effects of Combined Application of Organic and Inorganic Fertilizers on Rice Growth and Agronomic Efficiency in Saline Soil

Aiming at the salinity stress problems in rice root growth in the paddy soil of coastal saline-alkali soil, and the consequent low nutrients use efficiency, afield experiment was conducted to study the effects of combined application of organic and phosphate fertilizers on root growth in different growth stages, yield and nutrients use efficiency of rice in coastal saline soil. The experiment had two factors, including three carbon levels:(1) C0, no carbon; (2) C1:low carbon, 450 kg/hm²; (3) C2:high carbon, 900 kg/hm², and three phosphate fertilization (P) levels:(1) P0:no P; (2) P1:low P, P₂O₅64 kg/hm²; (3) P2:high P, P₂O₅128 kg/hm².Results showed that the total root surface area of T5 treated with low carbon and low P was significantly higher than those of high carbon and low phosphorus treatments (T7) and high carbon and high phosphorus treatments (T8), which increased by 25.2% and 30.2%, respectively. The total root volumes of low carbon treatments (T5, T6) were significantly higher than that of high carbon treatment in the harvest stage of rice. The rice yield and biomass of T5 were 10 245 and 9 550 kg/hm², respectively, and higher than others treatments. High seed setting rate was the reason for the highest yield of rice treated with low carbon and low P (T5) treatment. P accumulation of rice in low carbon and low P (T5) treatment was significantly higher than those in T6, T7 and T8 treatments, which were higher than 13.9%, 27.8% and 31.2%, respectively. The fertilizer contribution rate (FCR) and agronomic efficiency (AE) of P fertilizer under T5 treatment were significantly higher than others treatments. The partial fertilizer productivity (PFP) P fertilizer was significantly higher at low P input than that of high P input. In conclusion, compared with only inorganic fertilizer, combined application of organic fertilizer with P fertilizer could significantly promote rice root growth, increase rice yield and agronomic efficiency of P fertilizer in coastal saline soil. Low carbon and low P (T5, C450 kg/hm² and P₂O₅ 64 kg/hm²) treatment was the most favorable for rice root growth in coastal saline soil.