A survey of soil fertility and number of root-knot nematodes in dragon fruit orchards in Hainan
To clarify soil fertility and damage of root-knot nematodes in dragon fruit orchards in Hainan Island,a total of 186 soil samples were collected from 62 dragon fruit orchards,and the soil contents of nutrient elements such as nitrogen,phosphorus,potassium,calcium and magnesium,and the number of root-knot nematodes in the orchards were analyzed.The comprehensive soil fertility in the orchards was evaluated by using the fuzzy comprehensive evaluation method,and the correlation between the number of root-knot nematodes and soil nutrients was analyzed.The results showed that the average soil pH was 6.4 in the dragon fruit orchards,with the soil being generally neutral or weakly acidic in the orchards.The average soil content was 19.9 g/kg for organic matter,63.9 mg/kg for alkali-hydrolyzed nitrogen and 95.8mg/kg for available potassium content,all of which were in the state of deficiency.The soil contents of available phosphorus and exchangeable calcium were abundant or above,and the soil exchangeable magnesium content was in the medium level.The soil pH was positively correlated with the soil contents of organic matter,exchangeable calcium and magnesium,indicating that a neutral soil pH level was conducive to the accumulation of organic matter in the soil and had important significance for the availability of calcium and magnesium.The soil content of organic matter was positively correlated with the soil contents of alkali-hydrolyzed nitrogen,available phosphorus,available potassium,exchangeable calcium and magnesium,which indicated that the increase of soil organic matter would help to increase the contents of soil basic mineral nutrients.The number of root-knot nematodes in the dragon fruit orchards varied greatly.The maximum number of second-stage juveniles(J2)of root-knot nematodes in the orchards was 736 per 100 g dry soil,while the minimum number of the J2 root-knot nematodes was only 14 per 100 g dry soil.The incidence of the root-knot nematodes was different between the orchards in the north and the south of Hainan Island.On the whole,the number of the root-knot nematodes in the dragon fruit orchards was lower in the north than that in the south of Hainan Island.The soil pH and the soil contents of organic matter,available phosphorus and exchangeable calcium were positively correlated with the number of the root-knot nematodes in the soil.The findings of this survey showed that the comprehensive soil fertility index of the dragon fruit orchards in Hainan Island is at a high level.The changes of the soil pH and the contents of organic matter,available phosphorus and exchangeable calcium might have some reference for integrated management of the root knot nematodes in the dragon fruit orchards in Hainan.
Hainandragon fruit orchardsoil fertilitynumber of root knot nematodes
万方数据
维普
