华北地区地下滴灌春玉米出苗及生长对沟播开沟深度的响应

The Effects of Furrow Depth in A lternate Row Planting on Germination and Yield of Spring Maize under Subsurface Drip Irrigation in North China Plain

【目的】优化开沟播种技术模式,提高地下滴灌玉米出苗率及产量。【方法】在华北地区开展了春玉米田间地下滴灌试验,研究了不同开沟深度(H0处理:不开沟的平地播种;H10处理:沟深10 cm;H15处理:沟深15 cm)对土壤含水率、玉米出苗、生长和产量的影响。【结果】①种子埋设处土壤含水率随沟深增加而增大,灌35 mm的出苗水后,H10处理与H15处理种子埋设处土壤含水率分别比H0处理增大18.2%和25.7%;②H10处理和H15处理的种子出苗率均达到88%以上,分别比H0处理提高了14.6%和16.3%,差异达到显著水平(P<0.05),但H10处理和H15处理间的差异不显著;③玉米株高随沟深增加而增大,茎粗随沟深的增加而减小,H10处理和H15处理的叶面积指数显著高于H0处理;④H0处理的穗长、穗直径和穗粒数比H10处理和H15处理分别平均增大1.3%、1.6%、2.5%和7.6%、2.7%、11.1%,其中穗粒数和穗长显著高于H15处理;⑤综合穗数和百粒质量,H10处理产量最高,达到12980.0 kg/hm^(2),较H0处理和H15处理分别显著提高13.4%和7.5%。【结论】开沟播种技术适宜华北地区地下滴灌春玉米种植,适宜的开沟深度是10 cm。

【Objective】Subsurface drip irrigation(SD1)is a water-saving technique but difficult to keep the surface soil moist to ensure seed germination in drought-prone areas.Alternate row planting(AP)combined with the raised bed has been developed as an effective cultivation to moisten the surface soil.The purpose of this paper is to experimentally investigate the suitable furrow depth to improve seedling emergence and sustain crop yield.【Method】We took spring maize as an example and used the variety Xuntian 1102 as the model plant.The field experiment was conducted from May 2018 to September 2018 in the National Water-saving Irrigation Engineering Technology Research Center at Daxing,Beijing.The depth of the furrows was 0(CK),10 cm(H10)or 15cm(H15).In all treatments,the seeds were drilled to 5 cm deep from the soil surface and the irrigation amount prior to seedling emergence was 30mm,same in all treatments.During the experiment,we measured the changes in soil moisture,seedling emergence and the ultimate yield in each treatment.【Result】Alternate row planting combined with the raised bed significantly increased soil moisture at the drilling points to facilitate seed germination.Compared to CK,irrigating 35 mm of water prior to seedling emergence in H10 and H15 increased soil moisture in the region proximal to the seeds by 18.2%and 25.7%,respectively.The improved soil moisture increased the seedling emergence rate to more than 88%in both treatments,equivalent to a14.6%(H10)or 16.3%(H15)increase over the CK(P<0.05).The plant height and stem diameter both increased with the furrow depth,and the leaf area index in H10 and H15 was significantly higher than that in H0(P<0.05).The ear length,ear diameter and ear number in H10 were 6.8%,4.5%and 2.2%lower than those in CK,while the associated traits in H15 were 7.6%,2.7%and 11.1%lower than that in CK.Apart from ear length,no significant difference was identified between H0 and H15.H10 gave the highest ear number and 100-kernel weight,the highest yield-12.98 kg/hm^(2) m which was13.4%and 7.5%increase compared to that in H0 and H15 respectively(P<0.05).【Conclusion】AP combined with SDI with the furrow depth being 10 cm was suitable cultivation for spring maize production in north China.