华北平原旱地不同熟制作物产量、效益和水分利用比较
A comparative study of yield, cost-benefit and water use efficiency between monoculture of spring maize and double crops of wheat-maize under rain-fed condition in the North China Plain
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摘要: 针对华北平原地下水超采严重, 通过研究雨养旱作条件下不同熟制的产量、投入产出和水分利用效率, 探索华北平原缺水区雨养旱作条件下的节水种植制度, 可为地下水超采提供技术支撑。以当地主栽种植模式冬小麦和夏玉米一年2熟种植和春玉米一年1熟种植为研究对象, 通过大田试验对雨养旱作条件下冬小麦、夏玉米和春玉米3种作物构成的2种种植制度的产量、耗水、投入、产出进行分析。试验于2007-2013年在中国科学院栾城农业生态系统试验站进行, 该站为华北平原高产农区的典型代表。试验共设2个处理, T1为冬小麦 夏玉米一年2熟制, T2为春玉米一年1熟制。T1中的冬小麦生育期为每年的10月中上旬至翌年的6月中旬, 夏玉米为6月中下旬至10月上旬, 冬小麦品种大部分年份为'科农199', 夏玉米品种为'郑单958'。T2中春玉米的生育期为每年的5月中下旬至当年的9月上中旬, 品种为'农大108'、'浚单20'、'郑单958'和'先玉335'。试验区从2007年9月至2013年6月一直未灌溉, 为雨养旱作条件。研究结果表明, 雨养旱作条件下, 冬小麦产量基本稳定; 夏玉米和春玉米产量随年型不同波动较大, 尤其是夏玉米产量受播种时土壤含水量的影响较大, 很多年份由于干旱少雨, 玉米出苗时间推迟, 导致玉米产量大幅度降低。T1比T2虽然具有明显的产量优势, 增产34.1%, 但由于冬小麦生产投入较高, T1的净收益比T2低279.97元·hm-2。3种作物的生产投入中, 农资和机械投入比例最大, 劳动力投入占很小比例, 农资投入中, 化肥投入最高; 3种作物的产投比分别为1.42、2.66和3.42, 雨养旱作条件下冬小麦的产投比最低, 春玉米最高。从作物的耗水结构分析, 冬小麦生育期降雨较少, 以消耗雨季储存于土壤中的土壤水分为主, 春(夏)玉米生育期降雨较多以消耗降雨为主。目前, 生产上正在自发地压缩冬小麦的种植面积, 春玉米一年1熟种植面积迅速增加。因此, 在保证区域粮食安全的条件下, 通过调整农业种植结构可以控制水资源的过度开采, 保证农业持续发展。Abstract: In order to build a water-saving planting system and control water over-exploitation in the North China Plain, a field experiment was conducted to compare yield, cost-benefit and water use efficiency between spring maize monoculture and winter wheat-summer maize double cropping system under rain-fed conditions. The field experiment was conducted in 2007 2013 under rain-fed conditions at the Luancheng Agro-Ecosystem Experimental Station (LAS) of the Chinese Academy of Sciences (CAS), which is in the northern region of the North China Plain located at the base of Mount Taihang. Winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation is the most commonly used cropping system in the region. There were two treatments in the experiment, one was the winter wheat and summer maize rotation system (T1) and the other one was the single harvest of spring maize cropping system (T2). The winter wheat was grown from the first 10 days or mid-October to mid-June of the following year. Then summer maize was grown from mid-to-late June to early October, while spring maize was grown from mid-to-late May to the first 10 days of September. The varieties of winter wheat and summer maize used were 'Kenong199' and 'Zhengdan 958', respectively. Also the varieties of spring maize used were 'Nongda 108', 'Xundan 20', 'Zhengdan 958' and 'Xianyu335'. No irrigation was adopted in the experiment over the period from September 2007 to June 2013. The results showed that under rain-fed conditions, wheat yield was relatively stable while summer maize and spring maize yields varied with different climate years. Summer maize yield was especially strongly influenced by soil water content at sowing. Maize did not germinate normally in many seasons due to dry soil and little rain after sowing. Delayed summer maize germination decreased maize yield. Although crop yield under T1 treatment was 34.1% higher than that under T2 treatment, cost-benefit of T1 was 279.97 Yuan·hm-2 lower than that of T2 due to higher input of winter wheat. The proportions of agricultural materials and machinery investments were higher while labor input accounted for a small proportion of the inputs for the three crops. Fertilizer input accounted for a significant proportion in the agricultural materials. The input-output ratios of winter wheat, summer maize and spring maize were 1.42, 2.66 and 3.42, respectively. Under rain-fed conditions, input-output ratio of winter wheat was the lowest and that of spring maize the highest. Water consumption analysis suggested that soil water was the largest water source of winter wheat, while rainfall was the dominant source of spring and summer maize. In practice, farmers gradually reduced planting area of winter wheat and enlarged that of spring maize. In view of food security, it was needed to adjust the agricultural cropping system to control over-exploitation of groundwater resources and ensure sustainable development of agriculture in the study area.