Abstract The San Joaquin Valley produces more than 250 unique crops and much of the U.S. fruits, vegetables, and nuts. One of the main limiting factors for production in this region is reduced availability of water. Deficit irrigation is a management practice where plants receive less than full irrigation but only at certain growth stages to minimize yield loss or long-term impacts to the crop. Given the multiple roles of soil microorganisms in the soil system, it is important to asses any impact of deficit irrigation on soil microbial communities. In the present study, full and deficit irrigation treatments were applied for 7 years using furrow, microsprinkler, and surface drip irrigation systems in a peach orchard. In the seventh year, soil samples were collected before and after implementation of deficit irrigation treatments to investigate effects on soil microbial community biomass and composition. Results showed that the proportion of Gram-positive bacteria and actinomycetes were significantly higher in furrow irrigation, whereas fungi and Gram-negative bacteria were lower in proportion under furrow irrigation as compared with microsprinkler and drip irrigation methods. Canonical variate analysis showed that soil microbial communities markedly differed after deficit treatment in furrow and microspray irrigation, but remained similar in surface drip irrigation in deficit and full irrigation. This may be due to frequent irrigation in surface drip where soil surface remained moist most of the time as compared with furrow and microsprinkler irrigation methods where irrigation was less frequent.

中文翻译：

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不同灌溉方式和采后缺水灌溉条件下桃园土壤微生物群落组成

摘要 圣华金谷出产超过 250 种独特的农作物和大部分美国水果、蔬菜和坚果。该地区生产的主要限制因素之一是可用水量减少。亏缺灌溉是一种管理实践，在这种情况下，植物接受的灌溉少于充分灌溉，但仅在某些生长阶段进行，以尽量减少产量损失或对作物的长期影响。鉴于土壤微生物在土壤系统中的多重作用，评估亏缺灌溉对土壤微生物群落的任何影响非常重要。在本研究中，在桃园中使用犁沟、微喷灌和地面滴灌系统进行了 7 年的全灌和亏灌处理。第七年，在实施亏缺灌溉处理之前和之后收集土壤样品，以研究对土壤微生物群落生物量和组成的影响。结果表明，与微喷灌和滴灌相比，沟灌中革兰氏阳性菌和放线菌的比例显着较高，而沟灌下真菌和革兰氏阴性菌的比例较低。典型变量分析表明，在沟灌和微喷灌溉中亏缺处理后土壤微生物群落显着不同，但在亏缺灌溉和全灌溉下的地表滴灌中保持相似。