Research progress about the effect of sod-culture on the growth and development of fruit and orchard environment

Abstract: Sod-culture is a modernized orchard management pattern which is being popularized domesticand overseas, and as an orchard cultivation measure sod-culture may promote the fruit growth and development. In this paper, the effects of sod-culture on the growth and development of fruit were summarizedfrom the perspectives of root development, fruit development and arbuscular mycorrhiza formation of fruit.Research progress about the orchard environment of sod-culture was also analyzed from the viewpoints ofsoil biotic factors, abiotic factors and arbuscular mycorrhizal fungi colonization. The effects of sod-cultureon the growth and development of fruit are as follows: promote arbuscular mycorrhiza formation, growthand development, and increase the infection rate, which is beneficial to enhance the root absorption abili⁃ty of fruit; improve the stress resistance of fruit, in general, to improve fruit quality, is conducive to plantprotection of orchard and fruit green production. The effect of sod-culture on the orchard environment isas follows: improve soil organic matter content, meanwhile, improve the physicochemical properties ofsoil. Sod-culture could also promote the activities of the soil microbial and enzymatic, thus improve thesoil fertility. The grass roots played an important part to improve the soil structure, include soil-reinforce⁃ment and moisture conservation. Sod-culture promotes arbuscular mycorrhizal fungi colonization that ismore beneficial for improving the arbuscular mycorrhizal fungi diversity in the rhizosphere soil of fruiter.Compared with clean cultivation, the vesicles, arbuscules and total colonization rate and spore density arehigher in sod-culture soil, and the populations of rhizospheric microbes are higher. Sod-culture promotethe growth of the soil arbuscular mycorrhizal fungi, at the same time enhance the arbuscular mycorrhizalfungi’s ability to infect the root, arbuscular mycorrhizal fungi hyphae stretch in the soil inside, when con⁃tact with the root, tend to infect the root, and through the bridge between the hypha, promotes the transferof nutrients to the fruit. Grass of high infection rate promote the growth of arbuscular mycorrhizal fungi inthe soil and arbuscular mycorrhiza, and promote root system to absorb moisture and phosphorus nutritionutilization, improve the fruit physiological metabolism, improve fruit quality. Grass can stimulate arbuscu⁃lar mycorrhizal fungi colonization, increase the activity of soil phosphatase significantly, and stimulate thedevelopment of mycorrhiza, arbuscular mycorrhiza promote by the fruiter to grow. Secreted by the arbuscu⁃lar mycorrhizal fungi hypha and spore wall of specific glycoprotein Glomalin can prevent loss of the waterand nutrient in the soil aggregate. Glomalin related soil protein can stabilize soil aggregate. Grass canstimulate soil hypha growth, significantly increase Glomalin related soil protein and soil organic carbonconcentration. The seasonal and circadian rhythm fluctuation of soil temperature is minimized; and im⁃prove the orchard temperature and humidity. However, in insufficient water supplying orchard and particu⁃larly in the seedlings of fruit, and the water competition between the grass and the fruit could causedrought stress, thus restrained the vegetative growth and reduced the growth vigor. The prospect of thissod-culture was also looked forward, and the main purpose of this paper is to offer some references for theapplication and promotion of sod-culture in orchard. According to the research achievements that prede⁃cessors have obtained, we proposed some emphasis as follows: (1) According to the specific conditions offruiter and orchard, choose the appropriate sod-culture model and grass species. The ideal herbaceousgrass species should provide enough ground cover, shallow root, less water and fertilizer competitiveness,higher mycorrhizal infection rate and can promote fruiter root absorption function; (2) Selection of suitablesowing time, sowing depth and planting density: suitable sowing time can make the critical period of waterfor grass and fruiters stagger, so that the peak time of water and fertilizer demand to reduce the time; sowing depth of research significance and the selection of shallow grass species consistent, in the space stag⁃gered the overlap for water and fertilizer demand between grass and fruiter; the planting density will affectthe strength of grass and fruit competition; (3) determine the age of grass: through the timely updating ofgrass to solve the grass after years of grass aging problem; (4) determine the clipping cycle and cutting theway: cutting can inhibit grass root function, reduce its absorption of water and fertilizer, and through thefruiter disk cover mowing to improve soil fertility. Unreasonable way of clipping may damage the soil structure, so different grass species should take different and appropriate management measures.