摘要
本文探讨毛竹的叶营养诊断,以指导竹林施肥。研究内容包括叶分析的正确采样方法,用传统的临界值法和近期发展起来的新方法——DRIS诊断毛竹肥料试验的营养状态。结果表明: 1.毛竹的孕笋中期是采样的最佳时期;二年生立竹中部枝叶是取样的理想部位;一个叶平均样品至少采自5个单株才能达到分析精度的要求。 2.不同立竹结构对临界浓度标准有影响,每亩立竹250株以上的竹林,N、P浓度临界值分别为2.6％和0.13％,理想值为2.8％和0.16％。密度稀疏或钩梢竹林,N浓度临界值和理想值为2.9％和3.1％。新竹产量与N、P浓度反应相一致。 3.DRIS诊断参数从三年新竹产量大于3500kg/亩的高产群计算出来。DRIS诊断使用N、P、K、Si四组叶分析资料,诊断结果与临界值法基本一致。DRIS法的好处在于可以对营养平衡状况和需求顺序作出判断。但是养分相对不足或过量也可能误诊。考虑到森林立地条件的不均一性,应该推荐两种方法同时并用。
The present study was conducted to seek the diagnoses of bamboo nutrient state so as to guide its fertilization. Research contents included methods of tissue sampling for foliage analysis, and evaluation of nutrient status of field bamboo fertilizer experiments by the traditional critical value method and DRIS method which has been developed recently.The results are as follows:1. Tissue samples used for foliage diagnoses should be collected during the middle of shooting stage, and from the median branches of crown with 2-year age bamboo trees. In order to represent the nutrient content of plants, 5 single bamboos, at least, were needed to be collected for a mean sample.2. Critical value standards were affected by the structure of standing bamboos. As standing bamboos had more than 250 culms per mu (1/15 ha), N, P critical values were respectively 2.6 % and 0.13 %; optimum values were 2.8 % and 0.16 %. With sparse standing bamboo trees, or of which top parts of crown were cut off, N critical and optimum values appeared to be a little high up to 2.9 % and 3.1 %. The output responses of new culms, accumulating in 3 years, agreed with N, P concentration levels.3. DRIS reference values were obtained from the high-yield population of fertilizer experiments (yield 3500kg per mu). DRIS method was evaluated utilizing 4 data sets of N, P, K, Si. In general, where the critical value method made a diagnosis, it agreed with DRIS. DRIS had advantage over the critical value method to assess the status of nutrient balance of plant and nutrient order of requirement. But incorrect diagnoses might occur as nutrients were relative insufficencies or excesses. Considering the variety of forest sites, both the above methods should be recommended together for nutrient diagnoses in bamboo forests.
出处
《林业科学研究》
CSCD
北大核心
1989年第1期15-24,共10页
Forest Research
关键词
毛竹
叶诊断
临界值标准
DRIS
Phyllostachys pubescens
foliage diagnosis
critical value standard
DRIS
