覆草?施肥模式对板栗叶片功能性状与果实产量品质的影响

  目的  合理施肥与地表覆盖是干旱地区板栗高产优质的必要措施，本研究依据河北省迁西县当地实际情况提出一个优化的行间覆草和有机无机肥配施土壤管理模式，并进行效果验证，旨在为其改进和推广提供理论依据。  方法  以8年生板栗品种‘燕山早丰’为研究对象，采用裂区试验设计，主处理为行间覆草（GC）和清耕（CT），副处理为4个施肥处理，即单施无机肥（F）、单施有机肥（M）、有机肥与无机肥配施（F + M）和不施肥（CK），于2019年和2020年连续两年研究覆草?施肥模式对板栗叶片功能性状与果实产量品质的影响，运用主成分分析法对各处理28项指标进行综合评价，筛选出最佳土壤管理模式。  结果  （1）各施肥处理的新梢长度和粗度、叶面积、百叶干质量、百叶厚以及叶片矿质元素含量均有不同程度增加，且GC（F + M）处理显著高于其他处理。（2）地表覆草和不同施肥处理均可提高叶片叶绿素含量、光合速率和水分利用效率，增量最为明显的是GC（F + M）处理，分别比GC（CK）提高了6.00%、20.13%和44.87%。（3）有机无机肥配施（F + M）对于提高板栗坐果率、出实率、单粒质量和单株产优于单一施肥处理，其中GC（F + M）和CT（F + M）处理的单粒质量分别可达到10.32和9.92 g，较CT（CK）分别提高了26.01%和21.12%。（4）不同覆草?施肥模式处理的单株产量增幅为4.95% ~ 45.21%，GC（F + M）处理的淀粉和可溶性糖含量较CT（CK）处理分别提高了13.04%和36.57%。（5）主成分分析结果表明，GC（F + M）处理综合得分最高，其次为GC（F）处理，然后是CT（F + M）和CT（F）处理，说明有机无机肥配施比单施无机肥更有利于板栗枝条和叶片的生长发育，以及光合性能和果实产量品质的提高。  结论  在迁西干旱地区板栗栽培中，地表覆草?有机无机肥配施模式是该地区板栗提质增产的最适土壤管理方式。 

Effects of grass mulching-fertilization mode on leaf functional characters and fruit yield as well as quality of Castanea mollissima

  Objective  Reasonable fertilization and surface mulching are necessary measures for high yield and quality of Castanea mollissima (Chinese chestnut) in arid areas. This study proposed an optimized soil management model of interrow mulching and combined application of organic and inorganic fertilizers based on the local actual situation in Qianxi County, Hebei Province of northern China, and verified the effect to provide a theoretical basis for its improvement and promotion.   Method  This experiment took the 8-year-old Chinese chestnut variety Castanea mollissima ‘Yanshanzaofeng’ as the research object, adopted a split-plot design, and the main treatments were inter-row grass covering (GC) and clearing (CT), the secondary treatments were 4 fertilization treatments, single application of inorganic fertilizer (F), single application of organic fertilizer (M), combined application of organic fertilizer and inorganic fertilizer (F + M) and no fertilization (CK). In 2019 and 2020, the effects of grass mulching-fertilization mode on leaf function and fruit yield and quality of Chinese chestnut were studied for two consecutive years. Finally, the principal component analysis (PCA) method was used to comprehensively evaluate the 28 indicators of each treatment, and the best soil management mode was selected.  Result  The length and roughness of shoots, leaf area, dry quality of louver, thickness of louver and mineral element content of leaf increased to different degrees in each fertilization treatment, and the GC(F + M) treatment was significantly higher than that of other treatments. The chlorophyll content, photosynthetic rate and water use efficiency of leaves could be improved by surface covering grass and different fertilization treatments. The most obvious increment was GC(F + M) treatment, which was 6.00%, 20.13% and 44.87% higher than GC(CK), respectively. The combined application of organic and inorganic fertilizer (F + M) was better than single fertilization in improving fruit setting rate, fruit yield rate, single grain quality and single plant yield of Chinese chestnut. Among them, The single grain quality of GC(F + M) and CT(F + M) treatments could reach 10.32 and 9.92 g, respectively, which were 26.01% and 21.12% higher than that of CT(CK). The yield per plant increased by 4.95% to 45.21% under different grass mulching-fertilization modes, and the content of starch and soluble sugar in GC(F + M) increased by 13.04% and 36.57%, respectively compared with CT(CK). The result of principal component analysis showed that GC (F + M) treatment had the highest comprehensive score, the second treatment was GC(F) treatment, the third was CT(F + M) and the fourth was CT(F) treatment. It showed that combined application of organic and inorganic fertilizers was more beneficial to the growth and development of Chinese chestnut branches, as well as the improvement of photosynthetic performance and fruit yield and quality than single application of inorganic fertilizer.   Conclusion  In the cultivation of Chinese chestnut in arid area of Qianxi County, the mulch-organic and inorganic fertilizer combined application model is the most suitable soil management method for improving quality and increasing yield of Chinese chestnut in this area.