RESUMEN
Irrigation and fertilization are indispensable links in the jujube planting industry in southern Xinjiang, China. Regulating the relationship between fertilization and irrigation can effectively reduce costs and improve economic efficiency. A 2-year water and fertilizer optimization coupling test was conducted to determine the optimal water and nutrient supply scheme. The three-factor randomized block experiment included water (W), nitrogen (N), and phosphorus (P). According to the principal component analysis of each index, each treatment's comprehensive score was obtained. Using yield and economic regression models, the theoretical value and yield value of the optimal economic benefit are inferred. When W, N, and P were applied together, the fruit quality and yield of each treatment significantly differed, and the vitamin C, soluble sugar, and sugar-acid ratio increased significantly with an increase in N fertilizer. However, the titratable acid decreased. An increase in irrigation and nitrogen application significantly increased fruit yield. The comprehensive score was the highest in the N4P3W2 treatment, which improved fruit quality, and the lowest in the N3P3W2 treatment. When the amounts of N, P, and W were 275.56 kg hm-2, 413. 66 kg hm-2, and 7278.19 m3 hm-2, respectively, the theoretical economic benefit was the best. The N4P3W2 treatment is the optimal treatment.
RESUMEN
Effects of three compound growth regulators formulated with hypersensitivity protein, spermidine, salicylic acid and DA-6 (diethyl aminoethanol hexanoate) were tested on Xinjiang Jun Jujube. The doses of compound growth regulators were named as A (Hypersensitivity protein + spermidine + salicylic acid at the rate of 30 mg/L, 0.1 mmol/L and 0.25 mmol/L, respectively), B (Hypersensitive protein + spermidine + DA-6 at the rate of 30 mg/L, 0.1 mmol/L and 30 mg/L, respectively) and C (Spermidine + salicylic acid + DA-6 at the rate of 0.1 mmol/L, 0.25 mmol/L and 30 mg/L, respectively) versus a control group CK (contained only water). Fruit anatomical structures were compared after spraying. The results indicated that after spraying, the thickness of the upper and lower epidermal cells and the stratum corneum were increased. However, the upper epidermal stratum corneum became significantly thicker than the lower epidermis. Spraying with A improved the thickness of upper and lower epidermal cells, stratum corneum, the central vein and mesophyll. The cumulative effects of all these changes in leaf and fruit anatomical structures provided the resistance of the experimental fruit plant to stress. While the B and C regulators had inhibitory effects. So, the results obtained after spraying A category were beneficial to improve the stress resistance of the fruits. The length and cell area of pericarp and sarcocarp cells in the treatment groups were not changed significantly. But the length, number of sarcocarp cells and number of gaps were lower than those in the CK. This study can provide new measures for improving plant resistance in jujube production.
RESUMEN
The rapid advancement of jujube industry has produced a large amount of jujube biomass waste, requiring the development of new methods for utilization of jujube resources. Herein, medium-temperature pyrolysis is employed to produce carbon materials from jujube waste in an oxygen-free environment. Ten types of jujube biochar (JB) are prepared by modifying different pyrolysis parameters, followed by physical activation. The physicochemical properties of JB are systematically characterized, and the adsorption characteristics of JB for NO3- and NH4+ are evaluated via batch adsorption experiments. Furthermore, the pyrolysis and adsorption mechanisms are discussed. The results indicate that the C content, pH, and specific surface area of JB increase with an increase in the pyrolysis temperature from 300 °C to 700 °C, whereas the O and N contents, yield, zeta potential, and total functional groups of JB decrease gradually. The pyrolysis temperature more significantly effects the biochar properties than pyrolysis time. JB affords the highest adsorption capacity for NO3- (21.17 mg·g-1) and NH4+ (30.57 mg·g-1) at 600 °C in 2 h. The Langmuir and pseudo-second-order models suitably describe the isothermal and kinetic adsorption processes, respectively. The NO3- and NH4+ adsorption mechanisms of JB may include surface adsorption, intraparticle diffusion, electrostatic interaction, and ion exchange. In addition, π-π interaction and surface complexation may also be involved in NH4+ adsorption. The pyrolysis mechanism comprises the combination of hemicellulose, cellulose, and lignin decomposition involving three stages. This study is expected to provide a theoretical and practical basis for the efficient utilization of jujube biomass to develop eco-friendly biochar and nitrogenous wastewater pollution prevention.
