聚天门冬氨酸缓释复合肥显著提高甜玉米鲜穗产量与品质

  【目的】  持续稳定的养分供应是提高作物产量和品质的重要措施。研究不同种类缓控释肥对甜玉米鲜穗产量与品质的调控效应，为优质甜玉米生产中缓控释肥的施用提供依据。  【方法】  于2020年在河北省秦皇岛、石家庄和保定3地进行田间试验。供试品种为‘万甜2000’。共设置 5个处理，即控释掺混肥料 (T1)、控失聚能网复合肥 (T2)、聚天门冬氨酸缓释复合肥 (T3)、常规尿素 (T4) 和不施氮 (CK)。在玉米关键生育时期，测定植株干物重和全氮含量；在鲜穗采收期，测定鲜穗产量和籽粒营养品质，并进行品质评价。  【结果】  与T4处理相比，3个缓控释肥处理均能提高甜玉米穗长和穗粗，增加单穗鲜重和单位面积有效穗数，提高鲜穗产量。各类缓控释肥料可显著提高玉米鲜穗产量、氮肥利用率、氮肥偏生产力和氮肥农学效率，3地平均增幅分别为15.4%、57.2%、15.4%和67.0%；3个缓控释肥处理相比，T3处理下鲜穗产量、氮肥利用率、氮肥偏生产力和氮肥农学效率表现最优，比其它2个缓控释肥处理平均分别增加8.33%、55.6%、7.21%和22.6%。T3处理下甜玉米的食味品尝评分也有显著提高，比T4处理平均提高6.41%，同时也显著高于T1和T2处理，T3处理下甜玉米气味、果皮柔软度、甜度等较其它处理均有大幅改善。与T4处理相比，T1、T2和T3处理提高了甜玉米营养品质，其中T3处理下甜玉米可溶性糖、维生素C和维生素E含量最高。相关分析表明，籽粒N和P含量与其他指标无显著相关，籽粒K含量与籽粒可溶性糖、维生素C、维生素E、品尝得分均呈显著正相关关系；籽粒可溶性糖与维生素C、维生素E和品尝得分呈显著正相关。  【结论】  聚天门冬氨酸缓释复合肥对甜玉米鲜穗产量的增产效果最好，氮肥利用率、氮肥偏生产力和氮肥农学效率均最高。甜玉米品尝品质和营养品质最高，品质评定达到1等级。因此，施用聚天门冬氨酸缓释复合肥可以提高甜玉米鲜穗产量和品质。

Slow-release compound fertilizer containing polyaspartic acid effectively increases fresh ear yield and quality of sweet corn

  【Objectives】   Optimum and sustainable nutrient supply is an important measure to improve crop yield and quality. The effects of different controlled release fertilizers on the yield and quality of sweet corn were studied for selecting suitable controlled-release fertilizer for high value crop production.  【Methods】  Field trials were conducted in Qinhuangdao, Shijiazhuang and Baoding in Hebei Province in 2020. ‘Wantian 2000’ cultivar of sweet corn was used as the test material. Five treatments including controlled-release compound fertilizer (T1), controlled-release net compound fertilizer (T2), polyaspartic acid and slow-release compound fertilizer (T3), conventional urea fertilizer (T4) and no N fertilizer (CK) were set up. The plant dry weight and total N content were measured at the key growth stages, the fresh ear yield and grain nutritional quality were measured after harvest.  【Results】  Compared with T4 treatment, three kinds of controlled release fertilizers significantly increased the ear length and ear diameter of sweet corn, increased the fresh weight of single ear and the number of effective ears per unit area, and ultimately improved the fresh ear yield. All the controlled release fertilizers in the three sites significantly improved the fresh ear yield by 15.4%, N use efficiency by 57.2%, N partial productivity by 15.4% and nitrogen agronomic efficiency of maize by 67.0%, compared with common urea, and the best effect was obtained in T3 treatment, with increase of the above items by 8.33%, 55.6%, 7.21% and 22.6% respectively, compared with T1 and T2. The taste score of T3-grown sweet corn was 6.41% higher than that of T4 treatment, and higher than that of T1 and T2 treatment, with marked improvement in odor, peel softness, sweetness and other indicators. Compared with T4 treatment, T1, T2 and T3 treatment improved the nutritional quality of sweet corn, and T3 treatment had the highest content of soluble sugar, vitamin C, and vitamin E. Correlation analysis showed that there was no significant correlation between grain N and P concentration and other indexes, grain K concentration was significantly and positively correlated with grain soluble sugar, vitamin C, vitamin E and taste score; and grain soluble sugar was significantly positively correlated with vitamin C, vitamin E, and taste score.  【Conclusions】  Polyaspartic acid controlled-release compound fertilizer had the best yield-increasing effect on fresh ear yield of sweet corn, with the highest nitrogen use efficiency, partial nitrogen productivity and nitrogen agronomic efficiency, the sweet corn exhibited the highest taste quality and nutritional quality, and its quality evaluation attained Grade 1. Therefore, the application of polyaspartic acid controlled-release compound fertilizer can improve the fresh ear yield and quality of sweet corn.