Search

【Objective】The present paper aimed to clarify the comprehensive soil fertility status of pitaya orchards in Hainan province, and the spatial distribution and changing trend of soil nutrients in pitaya orchards in Hainan province were analyzed and predicted by means of survey sampling and statistical methods, so as to provide the basis for scientific fertilization and soil management of pitaya orchards.【Method】60 soil samples were collected from pitaya orchards in the main producing areas of Hainan province.Soil pH, organic matter, available nitrogen, available phosphorus, available potassium, exchangeable calcium, exchangeable magnesium, available copper and available zinc were used as evaluation indicators.Inverse distance weight interpolation method（IDW） was used to analyze the spatial distribution of each index, and used the factor analysis method combined with IDW to evaluate and predict the comprehensive soil fertility of the pitaya orchards in the survey area.【Result】The orchard soil in the survey area was neutral and slightly acidic, and 50% of the soil samples, pH were lower than 6.5; The organic matter content was moderately low, and some areas of Ledong and Sanya were insufficient; The average value of alkaline hydrolysis nitrogen was only 79.17 mg/kg, and the soil in the survey area was relatively lack of alkali-hydrolyzable nitrogen; The content of available phosphorus and available potassium were both high, and the average available phosphorus was 119.06 mg/kg, far exceeding its environmental risk threshold（60 mg/kg）; Orchards in the survey area the content of trace elements in the soil was relatively abundant. The IDW prediction map showed that the content of trace elements in Dongfang and Lingshui was high, and the content of Ledong and Sanya was low; Based on the analysis of the comprehensive score IFI, the results of the comprehensive fertility prediction of pitaya orchards in the entire study area using IDW showed that the eastern part of the study area, the comprehensive soil fertility of the orchards in the eastern and western regions of the study area was relatively high, while the soil comprehensive fertility of the orchards in the central part of Ledong and Sanya was relatively low.【Conclusion】The pitaya orchards in Ledong and Sanya still need to increase the input of organic fertilizers or increase the application of lime to improve the soil pH and supplement the medium and trace elements; The orchards in the survey area need to increase the input of nitrogen fertilizer and control the application of phosphate fertilizer. [ABSTRACT FROM AUTHOR]

Background and objective: Hainan province is a pepper base in China and its traditional production uses furrow fertigation, resulting in not only water and fertilizer waste but also nutrient leaching and contaminating the environment. The purpose of this paper is to explore suitable irrigation and fertilization methods to improve water and fertilizer use efficiency without compromising pepper yield. Method The experiment was conducted in field plots with four different irrigation - fertilization combinations: furrow irrigation without fertilization (CK), furrow irrigation with fertilization of 470.70 kg/hm2 of N + 511.22 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O (F1), furrow irrigation with fertilization of 376.55 kg/hm2 of N + 314.83 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O (F2), mulched micro-spray with fertilization of 376.55 kg/hm2 of N + 314.83 kg/hm2 of P2O5 + 526.39 kg/hm2 of K2O. In each treatment, we measured yield and fruit quality, photosynthesis, root growth, nutrient accumulation and nutrient distribution in soil, as well as water and fertilizer use efficiency. Result When N and P were initially high in the soil, F1 and F2 did not show significant difference in their yield, fruit quality, root growth, photosynthesis and accumulation of N, P and K in the plant. In contrast, F3 increased the yield, transpiration, root length, root surface area, root volume, accumulation of N, P and K by 8.03%, 16.91%, 60.69%, 43.00%, 40.37%, 19.30%, 14.19% and 14.61%, respectively, compared to F2; it also showed significant differences in fruit quality, net photosynthetic rate, stomatal conductance and intercellular CO2 concentration from F2. Compared with F1, F2 reduced the contents of total N, ammonium N, total P and available P in the 0-20 cm and 20-40 cm of soil after the harvest, reduced the apparent surplus N and P, and improved the partial productivity of N and P fertilizers. Compared with F2, F3 increased the contents of total N, nitrate N, ammonium N, total P and available P in the 0-20 cm of soil, reduced the apparent surplus N and P, and improved the production rate of the irrigation water.Conclusion For all treatments we compared, mulched micro-spray irrigation with reduced fertilization (F3) improved yield, water and fertilizer use efficiency of the pepper. [ABSTRACT FROM AUTHOR]