Influence of rhizosphere ventilation on soil nutrient status, root architecture and the growth of young peach trees

Abstract

The peach tree root respiration rate is high, which requires large amounts of oxygen. When the rhizosphere oxygen content is poor, the root respiration and energy metabolism are restrained which will have negative impacts on peach trees growth, fruit quality and yield, especially during high temperature and rainy season. Our objectives were to investigate the relationship between rhizosphere ventilation and orchard soil enzyme activity, nutrient status, root architecture and growth of young peach trees. Two-year-old ‘Chunmei’ peach (Prunus persica L. Batsch) was subjected to various treatments (Treatment 1 [T1]: ventilation every three days; T2: ventilation every six days; T3: natural ventilation; Control: no ventilation) under field cultivation conditions. The soil oxygen content decreased and subsequently increased during the growth period, reaching a minimum in August. The rhizosphere soil oxygen content was higher under ventilation treatment than control, and T1 markedly increased the rhizosphere soil oxygen content. The rhizosphere soil available K and organic matter decreased while the rhizosphere soil available N and available P content increased and the soil enzyme activity was improved under ventilation treatments. The root activity and root nitrate reductase activity increased under ventilation treatments. Under T1, the total root surface area, total root length and number of first lateral root and second lateral root were increased significantly, but the average root diameter and the average length of first lateral root was reduced significantly, the branching angle between first lateral root and vertically downward direction was decreased, the number of small angle was increased. T1improved leaf functions and increased the net photosynthetic rate. Under T1, the leaf chlorophyll content and leaf protective enzyme activity (Superoxide dismutase, Guaiacol peroxidase and Catalase) increased markedly in the middle- and late-growth period and leaf senescence was postponed. The total nitrogen, phosphorus and potassium contents of young peach roots, shoots and leaves, as well as shoot growth, leaf weight and leaf area, increased under T1.