学术
砾石直径和补灌量对砂田西瓜根系分布的影响
王亚军[1] 谢忠奎[1] 刘大化[2] 魏兴琥[1] 张志山[1]
[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000 [2]陇南市农业技术推广总站,甘肃陇南746000
摘 要:
采用剖面取样分析方法对砂田西瓜4种补灌量（0mm，23mm，4mm5和68mm）和三种粒径（2～5mm，5～20mm和20～60mm）砾石覆盖及不覆盖对照的根系分布进行了研究。结果表明，砂田西瓜有一个发达的根系，根系最长可扩展到1．5m的深度，但83％以上的根系集中在1m以上的土层，西瓜田覆盖砾石比对照的根系长度密度增加75％以上。砾石直径20～60mm的覆盖处理，RLD显著高于2～5mm直径的处理，降雨量较高的2002年，顶部50cm土层有更多的根系，降雨量少的年份，下部土层的根系明显增多，但整个土层的总根系长度低于降雨较多的年份。2001年补灌45mm和68mm处理的根系长度密度明显高于不补灌的处理，但2002年随补灌量的增加，下部土层根系长度密度减少。降雨少的2001年，补灌增加了西瓜根系的长度密度、蒸散量、产量和水分生产率，而降雨多的2002年，补灌后根系长度密度减少，水分生产率降低。不同直径的砾石覆盖，产量没有显著差别，但由于大粒径砾石覆盖增加了土壤蒸发，虽然根系长度密度增加，但水分生产率降低。结果说明，砾石直径、降雨和补灌量对砂田西瓜的根系分布有明显的影响，用5～20mm粒径砾石覆盖，并保持适度的水胁迫不仅有利于根系的扩展，而且能提高西瓜的水分利用率。[著者文摘]
文章出处:
《中国沙漠》-2006年26卷5期 -820-825页
栏目信息:
分 类 号:
文献标识码:
A
文章编号:
1000-694X（2006）05-0820-06
Impact of Gravel sand Mulch with Different Size Grain and Supplemental Drip Irrigation on Watermelon （Citrullus lanatus） Root Distribution
WANG Ya-jun, XIE Zhong-kui, LIU Da-hua, WEI Xing-hu, ZHANG Zhi-shan （1 .Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2.Longnan Station of Agricultural Technology Extension, Longnan 746000, Gansu, China）
Abstract:
Using the trench profile wall method we have investigated and compared the watermelon root distribution under four-drip-irrigation depth treatments （0 mm, 23 mm, 45 mm and 68 ram） and two soil cover treatments in fields （different grain size gravel-sand mulch and non-mulched control）. In the mulched field, watermelon yield decreased significantly with irrigation decreasing in 2001, a year with insufficient rainfall, but the yield did not differ significantly from those in 2002, a year with more rainfall. Water use efficiency （WUE） differed significantly between years, and increased with the increasing of root length density （RLD）. The RLD differed greatly among treatments. The RLD was obviously higher in 68 mm supplement irrigation field than that with lower or not irrigation. Besides, RLD was higher in the top 50 cm of soil in 2002 than in 2001. Compared with the control the gravel-sand mulch method could increase watermelon RLD by 75 %. Watermelon roots could reach the depth of 1.5 m in mulched fields, but most roots （more than 85.3% in 2001 and 92.5% in 2002） in the non-irrigated control were found in top 100 cm of soil. The treatment mulched with 20-60 mm diameter grain of gravel had denser root than treatment with 2-5 mm size. These results demonstrated that gravel size, rainfall and irrigation can affect the distribution of roots. Moderate water deficits can increase root length, then heighten the WUE of watermelon.[著者文摘]
Key words:
gravel-sand mulched field; watermelon; roots; supplemental irrigation; grain size of gravel
基金资助:
中国科学院农办项目（NK十五-C-09）资助
更多>>免费文章
cqvip.com