诊断施肥综合法（DRIS）在渭北旱塬红富士苹果营养诊断中的应用

本研究通过提前叶片采样时期,运用诊断施肥综合法(DRIS)对不同产量水平红富士苹果进行了叶片矿质营养诊断,以期为早期红富士苹果营养诊断与科学施肥提供依据.测定诊断结果表明,渭北旱塬红富士苹果叶片N、P、K、Ca、Mg、Cu、Fe、Mn、Zn的适宜值分别为26.04±3.50 g·kg-1、2.84+0.74 g·kg-1、15.05±4.08 g·kg-1、14.25±3.04 g·kg-1、3.15±0.73 g·kg-1、12.69±3.14 mg· kg-1、262.87±82.05 mg·kg-1、96.33±33.35 mg·kg-1、23.57±10.13 mg·kg-1.选择的DRIS诊断参数中,除N/Zn、Cu/P、P/Zn、Ca/Zn、Mg/Zn和Cu/Zn外,30种表示形式的变异系数均表现出低产组(＜ 25 kg·tree-1)大于高产组(＜25 kg·tree-1);高产组和低产组的养分不平衡指数(NII)分别为73和88.相对于高产组,低产组元素间关系更不平衡.总体而言,渭北旱塬区红富士苹果园除产量高于41.3kg· tree-需肥顺序排在第一位的元素为Cu外,其它均为P；需肥顺序排在第二位的元素高产为K,低产果园仅当产量低于10.2 kg·tree-1时为K,其余为Zn;而排在第三位的,高产均为Ca,低产均为Mg.

Application of DRIS in foliar nutrition diagnosis of Fuji apple trees in Weibei dryland of Shaanxi province

The diagnosis and recommendation integrated system (DRIS) method was adopted in foliar nutrition diagnosis to provide the basis for rational fertilization of Fuji apple trees in Weibei dryland. The results showed that the optimum concentrations of N, P, K, Ca, Mg, Cu, Fe, Mn and Zn in leaves of apple trees were 26.04±3.50 g·kg^-1, 2.84±0.74 g·kg^-1, 15.05±4.08 g·kg^-1, 14.25±3.04 g·kg^-1, 3.15±0.73 g·kg^-1,12.69±3.14 mg·kg^-1, 262.87±82.05 mg·kg^-1, 96.33±33.35 mg·kg^-1 and 23.57±10.13 mg·kg^-1, respectively. Except for N/Zn, Cu/P, P/Zn, Ca/Zn, Mg/Zn and Cu/Zn, the coefficients of variation of the low-yield group (<25 kg·tree^-1) were wholly larger than those of the high-yield group (>25 kg·tree^-1) for the obtained 30 parameters. The nutrient imbalance index (NII) was 73 in the high-yield group and 88 in the low-yield group. The mineral nutrients were more unbalanced in the low-yield group compared with the high-yield group. In general, for most Fuji apple orchards in the Weibei dryland, the requirement of P was ranked in the first place among all fertilizers, while for those with a yield above 41.3 kg·tree^-1, the requirement of Cu was ranked in the first place; the second element was K for the high-yield orchards and the orchards whose yield was lower than 10.2 kg·tree^-1, but it was Zn for other orchards; and the third element was Ca and Mg for the high-yield and low-yield orchards, respectively.