HighlightsApplication of biogas slurry can significantly improve the integrated growth, yield, quality of tomatoes.Water-nitrogen coupling model was established based on multi-index evaluation system of tomatoes.The optimal application quantitative range of water and nitrogen was obtained based on the water-nitrogen coupling model.Abstract. Biogas slurry, a liquid organic fertilizer, has been widely used in agricultural production. However, the characteristics of high water content and low fertility make it always applied empirically and a scientific and reasonable application of biogas slurry is urgent needed in practical agricultural production. This study aims to explore the effects of various biogas slurry concentrations on the yield, comprehensive nutritional quality (CNQ), irrigation water use efficiency (IWUE) and partial factor productivity of nitrogen (PFPN) of tomatoes in a greenhouse. Seven treatments, including T1(BS1:4; 0.8Ep), T2 (BS1:6; 0.8Ep), and T3(BS1:8; 0.8Ep), T4(BS1:4; 0.6Ep), T5(BS1:4; 1.0Ep), CK (no fertilization; 1.0Ep), CF (conventional chemical fertilization; 1.0Ep) were set up, where BS1:4, BS1:6,and BS1:8 are the volume ratio of biogas slurry to water, 0.6, 0.8, and 1.0 were crop dish coefficients, respectively. Ep is the evaporation amount of a 20 cm standard evaporating dish. The results showed that appropriate application of biogas slurry had a positive impact on crop growth such as total dry biomass, plant height, stem diameter and finally increased the yields, in which T1 treatment was the best. The fruit yield increased with the increase of biogas slurry ratio for treatments at the same irrigation level of 0.8Ep and the maximum yield of single tomato can reach 5.174 kg. The IWUE increased with the decrease of irrigation for treatments at the same biogas slurry ratio of BS1:4 and T4 treatment had the highest IWUE. The CNQ first increased and then decreased with the increase of biogas slurry ratio under the same irrigation level of 0.8Ep and T2 treatment obtained the highest CNQ; but the PFPN decreased with the increase of biogas slurry ratio and T3 treatment acquired the largest PFPN. Within an 80% confidence interval, when the irrigation amount was in a range of 39.233~43.134 L and the nitrogen quantities was 7.983~8.426 g, the yield, IWUE, CNQ, and PFPN can reach =80% of their maximums at the same time. Taking into account the growth, yield, fruit quality, and water and fertilizer use efficiency, T1 treatment was the best fertigation strategy for a higher production and better quality. The results can provide some help for scientific management of biogas slurry application in greenhouse. Keywords: Biogas slurry, Quality, Spatial analysis method, Tomato (Lycopersicum esculantum Mill), Yield.

This study aimed to investigate the material composition and transformation during composting of different kinds of livestock and poultry manures. Fresh cow manure (R1), pig manure (R2), and chicken manure (R3) were used as raw materials, and 10% corn stalk was selected as the leavening agent for aerobic static composting. The following results were obtained. After 30 days of aerobic composting, the mass reduction index of the R1, R2, and R3 piles was 48.94%, 47.94%, and 52.94%, respectively. Especially in the first stage (0–10 days) of the composting reaction, the mass reduction indices of the R1, R2, and R3 piles were significant, which were 21.45%, 22.73%, and 23.73%, respectively. During the composting process, the percentage of dissolved organic carbon in TC showed a downward trend, decreasing to 51.33% ± 1.25%, 57.35% ± 3.21%, and 52.34% ± 2.15%, for R1, R2, and R3, respectively. The percentage of ammonia nitrogen (AN) in total nitrogen (TN) in the piles R1, R2, and R3 first showed an increasing trend and then decreased, showing the highest values of 7.38%, 8.11%, and 9.22%, respectively.

NaOH pretreatment straw and chicken manure were mixed in different proportions to study the performance of anaerobic fermentation gas production of mixed materials with different proportions. The results showed that the pretreatment with 2% NaOH had the best effect on the gas production efficiency and cumulative gas production. After the pretreatment with NaOH, at the genus level, the main active flora was unidentified_Spirochaetaceae, unidentified_Prevotellaceae, uniden-tified_Lentimicrobiaceae, Lactobacillus, and Bacteroides. The highest peaks of amylase, protease, and cellulase activities were 308.73 IU/L, 121.03 IU/L, and 270.18 U/mL, respectively. The number of microbial colonies was positively correlated with the activity of the corresponding enzyme. With the increase of the proportion of straw in the raw materials, the activities of various hydrolases increased by 2.8%~28%. When the straw amount was 3%, the utilization rate of the raw material increased by optimization of C/N, and the efficiency of anaerobic digestion improved.

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Scientific and reasonable water and fertilizer regimes positively affected crop growth, yield, fruits quality and soil environment improvement. As a liquid quick-acting organic fertilizer to substitute chemical fertilizers, biogas slurry has been widely used in agricultural production. However, the lack of research on the proper comprehensive quality evaluation model and irrigation mode under biogas slurry limits the promotion and large-scale application of biogas slurry in agricultural production. In this study, three biogas slurry (BS) ratio (1:4BS, 1:6BS, 1:8BS; volume ratio of biogas slurry to water), three irrigation levels (W1, W2, W3) and three fertilizer control treatments (CF1, CF2, CF3) were conducted in field experiments. Eleven single indexes from four type qualities (external quality, taste quality, nutrition quality, storage and transportation quality) were adopted to establish the comprehensive evaluation index system of tomato. The principal component analysis, grey correlation analysis, membership function analysis and TOPSIS analysis model (based on the combination of objective entropy method and subjective analytic hierarchy process) were used to estimate the comprehensive quality of tomato fruits. Moreover, the objective combination evaluation mode based on overall diversity was used to evaluate the results obtained from the four independent comprehensive evaluation methods. The aim is to mitigate inconsistencies of multi-attribute evaluation models. The results showed that biogas slurry application was beneficial to the accumulation of aboveground biomass under the same irrigation amount, which can effectively improve the sugar to acid ratio and lycopene content of tomato. T3 (1:4BS, W3) and T1 (1:4BS, W1) obtained the highest yield and water use efficiency (WUE), respectively. The results of Kendall consistency test and Pearson correlation coefficients showed that there were good compatibility and high consistency among the four independent comprehensive evaluation models, and the combined quality evaluation model can be performed directly. As the correlation coefficients between combined evaluation model and each of four independent methods reached 0.965, the combined evaluation model was capable of reducing the differences of four independent comprehensive evaluation model. The combined quality evaluation results showed that T2 (1:4BS, W2) recommended strongly in this study could effectively improve the yield, quality and WUE of tomato.