太行山山前平原节水替代模式耗水特征分析

Water Consumption Characteristics of Alternative Crop Rotations in the Piedmont of Mt. Taihang

针对华北平原冬小麦-夏玉米模式的高耗水特征,结合当地作物生态适应性、粮棉安全及经济效益要求,从2003—2010年筛选确定了麦玉-春甘薯-春棉-春甘薯模式(粮棉薯)、黑麦草/春棉-花生-麦玉模式(粮棉油)、麦玉-花生模式(粮油)进行定位试验研究,分析3种模式替代麦玉模式的可行性。笔者重点研究了各模式的水分消耗特征,分析了一个轮作周期内(2006—2009年)各模式土壤贮水量、耗水量、各层次体积含水量变化和水分平衡。研究结果表明:与麦玉对照相比3种替代型模式土壤贮水量和不同层次水分利用表现出显著茬口效应,可更好的实现年际间水分互补利用;粮棉薯和粮油模式比麦玉模式生育期节水18%以上,2种模式下土壤贮水量平均每年增加20mm以上且与对照无显著差异,但这2种模式4年间土壤水分无效蒸发量显著高于对照。粮棉油模式与麦玉模式相比生育期节水5.4%,平均每年土壤贮水量增加13.8mm,显著低于麦玉模式(21.9mm),水分无效蒸发与对照无显著差异。替代型模式土壤贮水量整体水平较高,土壤水分变化率相对较小。因此,粮棉薯模式和粮油模式节水效果较好,粮棉油模式无明显节水效果,但综合粮食安全,粮油模式为最优替代模式。

North China plain is characterized by high water consumption of winter wheat and summer maize system, considered the local crops ecological adaptation and the safety requirements of grain and cotton production, we selected 3 different crop rotations to do this long-term experiment from 2003 to 2010. These plant patterns were wheat /maize-spring sweetpotato-spring cotton-spring sweetpotato （G-C-S）, ryegrass/ spring cotton-peanut-wheat/maize （R/C-P-G） and wheat/maize-peanut（G-P）. This study was to analyze the feasibility of the three rotation patterns instead of winter wheat and summer maize plantation. This research was focused on studying the water consumption characteristics of rotation patterns. Through the determination of soil moisture in a rotation cycle （2006-2009）, we analyzed the changes in soil water storage, water consumption, soil volumetric water content at all levels and the balance of soil water storage of different patterns. The results showed that compared with wheat and maize system, soil water storage and use of soil moisture at different levels of three rotation patterns showed more significant stubble effect. These three alternative rotations were better to achieve the annual complementary use of water. The water consumption of wheat/maize system was about 18% more than the patterns of G-C-S and G-P. The increase of water storage of G-C-S and G-P could reach to 20 mm a year which had no significant difference with wheat and maize system,but the invalid evaporation during the 4 years of the G-C-S and G-P was significantly higher than wheat and maize system. The water consumption of G-C-P was 5.4% less than the pattern of wheat/maize, the increase of water storage of G-C-P was about 18 mm which was significantly less than wheat/maize system. There was no significant difference between G-C-P and wheat/maize plantation in the invalid evaporation of moisture. The water-saving effect of G-C-P was better than wheat/maize system, but there was no significant difference between them. Of these three alternative patterns G-C-S and G-P plantation had the better effects to replace wheat/maize plantation. From the perspective of food security, G-P crop rotation was the best.