【摘 要】
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冬小麦—夏玉米一年两熟是河北平原主要的粮食生产种植制度。本文以山前平原藁城、辛集,黑龙港地区曲周、大名、深州、宁晋共6个县农户的正规调查和专家问卷调查以及生产潜力
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冬小麦—夏玉米一年两熟是河北平原主要的粮食生产种植制度。本文以山前平原藁城、辛集,黑龙港地区曲周、大名、深州、宁晋共6个县农户的正规调查和专家问卷调查以及生产潜力的模拟材料为依据,对河北平原冬小麦—夏玉米生产进行了系统的分析,以期对制约生产潜力发挥的限制因素有一个系统、客观的认识,为相关的科研机构、技术推广部门和政策制定部门提供研究和政策决策的依据。研究结果表明: 1.河北平原典型县冬小麦—夏玉米生产潜力的估算结果为:光温生产潜力模拟估算值为22916.6~26071.5kg/hm2,光温降水生产潜力模拟估算值为16860.5~18660.8kg/hm2。 2.高产攻关田产量可以作为各个县在当前技术水平下小麦—玉米种植制度技术潜力的参考指标,调查农户的产量在13462.5~14525.0kg/hm2,仅及高产攻关田产量的66.9%~73.2%。 3.制约河北平原冬小麦—夏玉米两熟生产的技术因素是:品种使用混乱;整地质量差;种植密度不合理,小麦种植密度上存在大播量、大群体的倾向,玉米种植密度普遍偏低;播期不当;底施有机肥很少,化肥的投入存在严重的比例失衡和数量不合理现象,小麦玉米两季投入的化肥总量在557.66~900.09kg/hm2之间,氮磷钾施用比例为1∶0.36∶0.09,农户比较重视小麦施肥,其中约66.8%(氮肥的60.8%、磷肥的85.1%、钾肥的60.1%)用于小麦,与高产攻关田施肥量相比(平均为N468.75kg/hm2,P2O5 211.25kg/hm2,K2O 148.75kg/hm2,比例为1∶0.45∶0.32,总养分828.75kg/hm2),受调查的多数农户氮肥用量过高而钾肥投入甚少;水利设施不足,灌溉时期不当;对病虫害缺乏全面和正确的认识。根据小麦—玉米两熟高、中、低产的划分标准(高产≥15000kg/hm2,中产11250~15000kg/hm2,低产≤11250kg/hm2),调查农户的产量水平大部分处于中产阶段,占74.6%;不同地区在明确限制因素的主次后针对性的提出了区域的主攻方向。 4.制约河北平原冬小麦—夏玉米两熟生产的经济因素是经济效益偏低,调查农户小麦—玉米两季平均产量为13759.58kg/hm2,净产值为10245.91元/hm2;与棉花相比,盈利仅为棉花的75.3%。 5.制约河北平原冬小麦—夏玉米两熟生产的社会因素是:土地经营规模小,农民的种粮积极性不高;农户获得技术信息主要是通过非正式的渠道,技术推广服务体系未能充分发挥功能;国家政策的宏观调控也在一定程度上影响小麦玉米生产潜力的发挥。
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