Optimization of growth and production parameters of walnut (Juglans regia) saplings with response surface methodology

Abstract

Straw mulching is an effective conservation tillage tool that utilizes waste resources and reduces environmental pollution. To determine the optimal levels of quality, placement and quantity of straw mulching, we performed a field experiment that used the Box–Behnken design combined with response surface methodology. The treatments designed for walnut saplings (Juglans regia) considered three independent variables: quality, placement, and quantity of straw mulching. Tree height of walnut saplings (THW) and net photosynthesis rate (NPR) were used as the response variables in a full, quadratic polynomial model. Analysis of variance (ANOVA) results showed that the selected models were significant (P < 0.05), expressing ideal relationships between the independent and dependent variables (R2 ≥ 0.9225). The optimum conditions for the THW and NPR responses were determined to be a straw mulching quality which mixed rice and rapeseed straws, a straw mulching placement which covered the entire soil surface of experimental plots, and a straw mulching quantity applied as 3 kg/m2 (i.e., the low level). This optimized scheme of straw mulching combinations offers an alternate choice for optimizing the growth and potential yield of walnut saplings, but practical field experiments should also be carried out to obtain more site-specific results.

Effects of straw mulching practices on soil nematode communities under walnut plantation

“…However, the mix straw mulching treatments with high SI and low EI values at different straw mulching distances were in quadrant C, which indicates a structured food web, medium soil enrichment, a moderately high C/N ratio, fungal decomposition channels, and no disturbance. Our previous research suggested that the mix straw mulching treatment had a moderate carbon nitrogen ratio (C:N) and that mix straw degrades more quickly than rice straw or rapeseed straw 9 . In addition, the mix straw may have provided stable moisture content and higher dissolved organic carbon and dissolved organic nitrogen than rice straw or rapeseed straw (Table 1 ), thus increasing nutrient availability and soil fertility levels.…”

“…With the growth of young walnut trees, the canopy width increases each year, so it is reasonable to designate the canopy radius at the coverage distance, considering the effect of canopy shading. In addition, we have previously reported that suitable straw mulching materials can promote the growth of walnut trees and increase the potential yield 9 . Therefore, it is an important step for the sustainable management of walnut orchards to determine suitable materials for straw mulch and location for straw mulch placement.…”

The influence of probiotic fermentation on the active compounds and bioactivities of walnut flowers

“…The walnut ( Juglans regia L.) is an economically important fruit tree worldwide with various health benefits (Song et al., 2018; Su et al., 2020). The walnut flower, one of the main by‐products from the production of walnuts, has high nutritive value and has always been used as traditional food and Chinese Medicine in China (Zhang et al., 2020).…”

Continuous Fixed-Bed Column Studies to Remove Polycyclic Aromatic Hydrocarbons by Degrading Enzymes Immobilized on Polyimide Aerogels

“…As indicated by the reported standard deviation (1.09), the values are close to average, that is, their dispersion is low. According to this study, the derived model's adequacy precision is 55.19, indicating it is suitable for application within the design space (Song et al, 2018). This preprint research paper has not been peer reviewed.…”