The Water And Fertilizer Technology For Regulation Ecosystem Of An Apple Orchard In Weibei Region

With the planting scale extending, the planting age increasing and the use of chemicalfertilizers rising, a series of problems like the soil desiccation being exacerbated which causedby the capacity of soil moisture regulation reducing and nitrate nitrogen accumulating in deepsubsoil had appeared. Therefore, it was necessary to controlling the apple orchard ecosystemto achieve the goal of the apple production with high quality, efficiency and sustainability. Soa measure of controlling the supply of water and fertilizer was proposed, which named“root-controlling technology by assembling water and fertilizer”. At the same time, soilmoisture, nutrients and root system growth status of different experimental treatments hadbeen analyzed in order to offer a scientific guidance for harmonious development of appleproduction technology, economic income of farmer, and the apple orchard ecosystem.The results were as follows:(1) Soil water storage at different locations during the year was best represented by abimodal curve with peaks in September and February. During the years, the average soil watercontent between the ridges (23.3%) was higher than that directly under the ridges (21.6%).This technology changed the spatial distribution of the soil moisture content. At the sameposition, the soil moisture content was higher between ridges in the plastic film-mulchedsystem than in the unmulched control treatment. In contrast, the soil water content directlyunder the ridges in the plastic film-mulched system was slightly lower than that in the control.The soil water content of ridging treatment in the0～200cm depth was higher than thecontrol treatment. Between the ridges, the soil moisture content in the200～600cm depthwas high and relatively stable. This is beneficial to the development of a healthy and stableecosystem in the orchard. In conclusion, the plastic film-mulch, ridge and furrow rainwaterharvesting system can increase water conservation, significantly improving rainwater useefficiency and increasing water availability in apple orchards.(2) The different mulching methods, which included “film over long wheat straw mulch”,“long wheat straw over film mulch”,“film over short wheat straw mulch” and “film overmaize straw”, not only could improve nutrient content of apple leaves and branches, but alsoenhance the yields and quality of apples. The nutrient content in the treatment “film over short wheat straw mulch” was significantly higher than that of the control and the yield, water useefficiency and ratio of excellent fruit in this treatment were highest among all managements.Altogether,“film over short wheat straw mulch” was the most appropriate soil management ofdual mulches.(3) Two artificial impermeable layers of red clay and test soil were built in soil, with athickness of3or5cm. Results showed that artificial impermeable layers with the twodifferent thicknesses were effective in reducing or blocking water infiltration into soil and hadhigher seepage controlling efficiency. Seepage controlling efficiency for the red clayimpermeable layer was better than that for the test soil impermeable layer. Among all thetreatments, the red clay impermeable layer of5cm thickness had the highest bulk density, thelowest initial infiltration rate (0.033mm·min-1) and stable infiltration rate (0.018mm·min-1)among all treatments. The red clay impermeable layer of5cm thickness could effectivelyincrease soil moisture content in upper soil layer which was conducive to raise the water andnutrient use efficiency. The approach could be applied to the apple production of dry landorchard.(4) Both of the water storage of “impermeable layer” treatment (F) and the “impermeablelayer+ridging” treatment (FL) could increase the water storage of soil (0～40cm), and theresult showed that the water storage of different treatment was FL（88.8mm）﹥F（85.9mm）﹥CK（84.4mm）for three consecutive years.(5) To analyze the soil moisture in0～300cm layer, it was divided into five0～40cm，40～60cm，60～80cm，80～140cm and140～300cm five sections. In plentiful rainfall year,the20～40cm layer had the largest soil moisture and the average soil moisture of treatment(F) and treatment (FL) were26.5%and26.2%respectively, both of which met or exceededthe field capacity and were14.9%and13.5%more than the control. While in low flow year(2012and2013), the20～40cm layer which treated by FL had the largest soilmoisture(23.2%and20.2%), however the largest soil moisture of the control occurred in the40～60cm layer (22.4%and19.7%).(6) Artificial impermeable layers could effectively block the trend of nitrate nitrogenleaching into deep soil layer. The nitrate nitrogen content of treatment F and FL, which was inthe impermeable layers, was significantly lower than the control treatment. The averagenitrate nitrogen content of different treatments in40～300cm soil layer were as follows: FL（62.39mg·kg-1）＜F（95.54mg·kg-1）＜CK（140.74mg·kg-1）.(7) The treatment F and treatment FL could create a good environment for apple’s rootgrowing. The total root length, root tips, total surface area and total area of projection oftreatment FL all were the highest among all treatments, which were higher34.6%,22.8%, 25.9%and64.3%respectively than the control treatment.(8)The apple trees that dealt with treatment FL had gained the best harvest, whichfollowed by apple trees dealt with treatment F. To be more specific, the treatment FL gainedthe highest yield per plant (23.84t·hm-2), which was higher than the control by23.2%, and thewater use efficiency of treatment FL (48.89kg·mm-1·hm-2) was also higher than the control by22.4%.In conclusion,“root-controlling technology by assembling water and fertilizer” nicelycombines the advantages of “artificial impermeable layer” and “plastic film-mulch, ridge andfurrow rainwater harvesting system”. It can gather the limited rainfall, and regulate andcontrol the fertilizer effectiveness by increasing the water content, than creating amicro-environment where the water content and fertilizer is high for the apple’s root. It caneffectively improve the soil moisture uses efficiency, block the trend of nitrate nitrogenleaching into deep soil layer and increase the quality and quantity of apple. It is a water andfertilization regulation technology and worthy of promotion.