不同剂量连作障碍调控肥对土壤物理性质和制种玉米经济效益的影响

Effects of Different Doses of Control Fertilizer for Continuous Cropping Obstacle on Soil Physical Properties and Economic Benefits of Corn Seed

【目的】研究不同剂量连作障碍调控肥对土壤物理性质和玉米经济效益的影响。【方法】在连作13 a的制种玉米土壤上,采用田间试验方法,以制种玉米连作障碍调控肥施用量为梯度设计7个处理,分别为:CK,0.85、1.70、2.55、3.40、4.25和5.10 t/hm^2。以不施肥为对照,每个试验处理重复3次,随机区组排列。【结果】随着连作障碍调控肥施用量由0.85增加到5.10 t/hm^2时,与对照比较,土壤总孔隙度、团聚体、饱和持水量分别增加了6.42%、14.63%和17.91%,土壤容重降低了11.11%,差异极显著(P<0.01);制种玉米株高、茎粗、生长速度、地上部分鲜重和地上部分干重分别增加了26.06%、32.12%、26.05%、48.05%和48.06%,差异极显著(P<0.01);制种玉米穗粒数、穗粒重和百粒重分别增加52.24%、46.06%和20.70%,差异极显著(P<0.01);制种玉米产量增加了46.04%,差异极显著(P<0.01);但1 kg连作障碍调控肥的增产量则随着连作障碍调控肥施用量的增加而递减为63.64%。【结论】连作障碍调控肥施用量大于3.40 t/hm^2时,施肥利润出现了负值,连作障碍调控肥适宜用量一般为3.40 t/hm^2,此施用量下,制种玉米的理论产量为6.91 t/hm^2,经济效益最好。

[ Objective] To study the effects of different doses of control fertilizer for continuous cropping obstacles on soil physical properties and the economic benefits of corn. [ Method] Field test method was used in 13 years continuous cropping soil of maize seed. Using field experiment method, in order to control corn continuous cropping obstacle of Fertilizer Design 7 treatments for the gradient were ： CK, 0.85, 1.70, 2.55, 3.40,4.25 and 5.10 t/hm^2, no fertilizer as CK, each treatment was repeated 3 times, randomized block design. [ Result] Along with the increase of continuous cropping obstacle control fertilizer from 0.85 t/hm^2 to 5. 10 t/hm^2, compared with the control, the soil total porosity, aggregates, saturated water content were increased by 6.42%, 14.63% and 17.91%, and soil bulk density decreased by 11.11%, which was a significant difference （P 〈 0.01 ） ; Maize plant height, stem diameter, growth rate, fresh weight and dry weight on the ground were increased by 26.06%, 32.12%, 26.05%, 48.05% and 48.06%, respectively with significant differences （P 〈 0.01 ） ; Corn kernel number, kernel weight and 100 kernel weight were increased by 52.24%, 46.06% and 20.70% with significant differences （P 〈 0.01 ）; The corn yield was increased by 46.04% with significant difference （P 〈 0. 01 ） ; but the increased yield of fertilizer per kilogram for continuous cropping obstacle decreased by 63.64% with the increased amount of the fertilizer. [ Conclusion] When the control fertilizer application amount of continuous cropping obstacle was more than 3.40 t/hm^2 , the nega- tive value in profit of fertilization appeared, from which it is clear that the amount should be better below 3.40 t/hm^2. Applying this amount, the theoretical corn yield is probably over 6.91 t/hm^2, reaching the best economic benefit.