2种不同岩性土壤上施肥后闽楠叶片DRIS营养诊断

DRIS Based Nutrient Assessment of Phoebe bournei Leaves After Fertilization in Two Different Lithological Soils

研究闽楠基于2种不同岩性土壤上造林后的施肥响应,通过诊断施肥综合法(DRIS)为造林后闽楠养分管理和平衡施肥提供参考依据。以2年生闽楠苗作为试验材料,在板岩(B)、煤系砂页岩(M)发育形成的土壤上设置N、P、K 3因素二次回归正交施肥试验,并采用DRIS图解法和指数法对2种不同的岩性土壤各处理组的闽楠叶片进行营养诊断以及养分临界值范围划分。结果表明,在板岩(B)土壤上,闽楠叶片元素的最佳比值范围分别为N/P=17.713±2.522,N/K=2.939±0.406,P/K=6.088±0.656;煤系砂页岩(M)土壤上,叶片元素的最佳比值范围为P/N=0.048±0.004、K/N=0.356±0.044、P/K=0.138±0.006。板岩土壤上,闽楠各处理对养分的需求次序均表现为P>K>N,低产组养分不平衡指数(NII)最大且不平衡程度更大,但其中以B10处理更趋于平衡;煤系砂页岩土壤上,闽楠各处理对养分需求次序表现为N>K>P,同板岩一样其低产组不平衡程度也最大,以M12的养分更趋于平衡状态。通过DRIS指数临界标准划分,板岩上闽楠叶片各元素的适宜质量分数范围为:N=18.961~26.010 g/kg,P=1.032~1.577 g/kg,K=6.046~9.709 g/kg;煤系砂页岩上为:N=20.050~29.730 g/kg,P=1.152~1.218 g/kg,K=8.167~9.073 g/kg。对2种岩性土壤上闽楠施肥后的营养诊断结果表明,板岩土壤上以B10处理即施用N:0 g·株^(-1)、P:6 g·株^(-1)、K:5 g·株^(-1)时对闽楠生长更有利;煤系砂页岩土壤上以M12施用N:12.5 g·株^(-1)、P:0 g·株^(-1)、K:5 g·株^(-1)时更适宜闽楠生长,但培育过程中应多注意根据闽楠生长养分的适宜范围对缺乏和过剩的养分及时调整以更好达到平衡养分的目的。

Based on the fertilization response of Phoebe bournei planted in two different lithological soils,the diagnosis and recommendation integrated system(DRIS)was used to provide a reference for the nutrient management and balanced fertilization of P.bournei after afforestation.Seedlings of 2-year-old P.bournei were used as test materials.A regression orthogonal fertilization experiment was set up with 3 factors(N,P,K)on the soils formed by the development of slate(B)and coal-measure sand shale(M).The DRIS graphical method and the index method were used to diagnose the nutrition of P.bournei leaves in each treatment group of two different lithological soils and to divide the nutrient critical value ranges.The results showed that the best ratio ranges of P.bournei leaf elements were N/P=17.713±2.522,N/K=2.939±0.406,P/K=6.088±0.656(in B);and P/K=0.138±0.006,K/N=0.356±0.044,K/P=0.138±0.006(in M),respectively.In the soil B,the order of nutrient requirements for each treatment was in the order of P>K>N,the nutrient imbalance index(NII)of the low-yield group was the largest,and the imbalance intensity was greater.Among them,the nutrients treated with B10 tended to be more balanced.In the soil M,the order of nutrient requirements was N>K>P,the degree of imbalance in the low-yield group was the largest,and the imbalance intensity was greater,but the nutrients in M12 tended to be more balanced.According to the critical standard of DRIS index,the appropriate concentration ranges in B soil were N=18.961-26.010 g/kg,P=1.032-1.577 g/kg,K=6.046-9.709 g/kg.In M soil,the ranges were N=20.050-29.730 g/kg,P=1.152-1.218 g/kg,K=8.167-9.073 g/kg.The results indicated that B10 treatment was more beneficial to the growth of the P.bournei seedlings in B soil with the application amounts of different nutrient elements per seedling of N:0 g·P^(-1),P:6 g·P^(-1),K:5 g·P^(-1),and in soil M they were N:12.5 g·P^(-1),P:0 g·P^(-1),K:5 g·P^(-1).It would be emphasized that adjustment should be carried out for the elements beyond the ranges mentioned above to achieve the goal of balancing nutrients.