不同地表覆盖方式对苹果园土壤性状及果树生长和产量的影响

Effects of different patterns surface mulching on soil properties and fruit trees growth and yield in an apple orchard

以黄土高原9年生红富士果园生态系统为对象,研究不同地表覆盖模式(清耕、生草覆盖、地膜覆盖、秸秆覆盖和砂石覆盖)对果园土壤性状及果树生长和产量的影响.结果表明:生草覆盖土壤水分剖面分异最低,砂石覆盖土壤水分剖面分异最高;砂石覆盖提高了根层水分含量,有利于果树对水分的利用.不同地表覆盖模式土壤热量状况变化显著,处理间差异明显,极端最高温度下降,但地膜覆盖处理夏季地温超过果树根系生长的上限温度,对果树根系生长和生理功能发挥不利.除地膜覆盖外,其他地表覆盖模式均能提高土壤CO2释放速率,其中生草覆盖的效果最为显著.不同地表覆盖模式对果树枝条类型比例及产量影响较大,砂石覆盖处理的中短枝比例和果实产量最高;生草覆盖处理的果实产量最低.因子分析结果表明,对于黄土高原沟壑区盛果期果园,砂石覆盖处理是较为适宜的地表覆盖模式.

Taking a nine-year-old Fuji apple orchard in Loess Plateau as test object,this paper studied the effects of different patterns surface mulching（clean tillage,grass cover,plastic film mulch,straw mulch,and gravel mulch）on the soil properties and fruit trees growth and yield in this orchard.Grass cover induced the lowest differentiation of soil moisture profile,while gravel mulch induced the highest one.In treatment gravel mulch,the soil moisture content in apple trees root zone was the highest,which meant that there was more water available to apple trees.Surface mulching had significant effects on soil temperature,and generally resulted in a decrease in the maximum soil temperature.The exception was treatment plastic film mulch,in which,the soil temperature in summer exceeded the maximum allowable temperature for continuous root growth and physiological function.With the exception of treatment plastic film mulch,surface mulching increased the soil CO_2 flux,which was the highest in treatment grass cover.Surface mulching also affected the proportion of various branch types and fruit yield.The proportion of medium-sized branches and fruit yield were the highest in treatment gravel mulch,while the fruit yield was the lowest in treatment grass cover.Factor analysis indicated that among the test surface mulching patterns,gravel mulch was most suitable for the apple orchards in gully region of Loess Plateau.