覆草和浇水量对桃树幼苗生长及土壤温湿度的影响

Effects of straw mulching and irrigation water quantity on peach growth and soil temperature,humidity

【目的】阐明不同水分条件下覆草对高温季节土壤水热的调节作用及对信阳五月鲜桃幼苗生长状况的影响,筛选较适宜桃树幼苗生长的节水栽培模式。【方法】2019年6—8月,以1年生五月鲜桃幼苗为试验对象,以干水稻秸秆为覆盖材料,设置覆草量0(CK)、2、4、8 kg/m2,设置浇水量0.6、0.9、1.8、3.0 kg,进行盆栽试验。对各处理下土壤温度、土壤含水量及桃树幼苗的株高、茎粗、叶绿素相对含量、病叶数进行测定、统计和分析。【结果】各覆草处理中土壤温度较对照均有不同程度降低,土壤含水量较对照均有不同程度提高,并且随着覆草量加倍,降温和保墒效果提高。在0.6 kg浇水量条件下,各覆草处理中土壤温度降低了5.06%~18.05%,土壤含水量提高了16.68%~32.22%;在0.9 kg浇水量条件下,各覆草处理中土壤温度降低了3.38%~17.46%,土壤含水量提高了10.03%~29.61%;而在1.8和3.0 kg浇水量条件下,覆草处理中土壤温度仅降低了1.89%~10.01%,土壤含水量仅提高了3.04%~14.74%。即覆草在低浇水量条件下的降温保墒效果优于高浇水量条件。与对照相比,各处理间桃树幼苗的茎粗无显著差异,但4、8 kg/m2覆草量处理下桃树幼苗的株高均有显著提高,并且高浇水量条件下生长较快,同时覆草处理下病叶数均低于对照。按照叶片叶绿素相对含量由高到低排列,各覆草量处理依次为8 kg/m2(32.07)、2 kg/m2(31.03)、4 kg/m2(29.12)、CK(27.40),并随着浇水量增加呈下降趋势,表明覆草在低浇水量条件下对叶绿素合成的促进作用较好。【结论】在夏季高温天气,覆草可以起到降温保墒的作用,并能进一步促进桃树幼苗的良性生长。结合各水分条件下覆草对土壤温湿度的调节效果,以及桃树幼苗生长指标的变化,初步认为0.9 kg低水分条件和8 kg/m2覆草量组合模式是较适宜信阳五月鲜桃幼苗生长的节水栽培方案。

【Objective】Clarifying the effect of straw mulching on the regulation of soil temperature,moisture and the growth of Xinyang Wuyuexian peach under different moisture conditions in high-temperature seasons,to select the most suitable water-saving cultivation models for peach seedlings.【Method】The one-year seedlings of Xinyang Wuyuexian peach was used as research materials mulched with rice straw according to 0(CK),2,4,8 kg/m2 gradient,at the same time,set irrigation quantity treatment according to 0.6,0.9,1.8 and 3.0 kg gradient for pot cultivation test from June to August in 2019.The soil temperature and moisture,plant height,stem thickness,SPAD,and the number of diseased leaves under different treatments were measured,recorded,and analyzed.【Results】Compared with control,the soil temperature of each mulching treatment decreased,and the soil water content increased to some extent.As the mulching amount doubled,the cooling and moisture retention effects increased.Treated with 0.6 kg irrigation quantity,the soil temperature of each mulching treatment decreased by 5.06%-18.05%,and the soil water content increased by 16.68%-32.22%.Treated with 0.9 kg irrigation quantity,the temperature of each mulching treatment decreased by 3.38%-17.46%and the water content increased by 10.03%-29.61%,while treated with 1.8 kg and 3.0 kg irrigation quantity,the soil temperature of the mulching treatment only decreased by 1.89%-10.01%,the water content increased only 3.04%-14.74%,which meant that the mulching had a better cooling and moisture retention effect under low moisture conditions.Compared with control,there was no significant difference in the stem thickness of the peach seedlings between the treatments,but the height of the peach seedlings under 4 kg/m2 and 8 kg/m2 mulching treatments was significantly increased,the growth was faster under high moisture conditions.At the same time,the number of diseased leaves under the mulching treatment was lower than that of the control.The leaf SPAD performance of each treatment was 8 kg/m2(32.07)>2 kg/m2(31.03)>4 kg/m2(29.12)>CK(27.40),and decreased with the increase of irrigation amount,which indicated that mulching had a better promotion effect on chlorophyll synthesis under low moisture conditions.【Conclusions】Under the high temperature in summer,straw mulching plays a role in cooling and preserving moisture,and can further promote the healthy growth of peach seedlings.Combined with the regulation effect of mulching on soil temperature and humidity under various water conditions and the changes in peach seedling growth indicators,it is preliminarily considered that the combination model of 0.9 kg low moisture conditions and 8 kg/m2 straw mulching is a more suitable water-saving cultivation plan for the young trees growth of Xinyang Wuyuexian peach.