Effects of different nitrogen application methods on microbial community structure of paddy soil at different rice growth stages were examined using phospholipid fatty acid analysis (PLFA) and Biolog technique. There were four treatments, no straw returning or fertilization (CK), straw returning +urea with the proportions of after wheat harvest, before rice transplanting, tillering stage and booting stage being 0622 (T1) and 3322 (T2), and straw returning+co-application of biogas slurry and urea with the proportion of after wheat harvest, before rice transplanting, tillering stage and booting stage being 3 (biogas slurry)3 (2biogas slurry+1urea)2 (urea)2 (urea)(T3). Results showed that T3 significantly increased soil available nitrogen contents at all growth stages, which was significantly higher at maturity stage than that at tillering and booting stages. T1-T3 had higher available phosphorus and available potassium contents at all growth stages compared with CK, which were higher at tillering stage than at booting and maturity stages. The interaction between growth stage and treatment in paddy soil significantly affected the contents of soil available nitrogen, available phosphorus and available potassium. (L)Dehydroascorbic Furthermore, carbohydrate, amino acid, polymer and carboxylic acid were the primary carbon sources for microbial community of paddy soil. T3 effectively enhanced soil carbon sources metabolic utilization intensity. The interaction between growth stage and treatment in paddy soil significantly affected the microbial utilization capacity of carbohydrates and carboxylic acids. Soil microbial biomass was significantly higher in T2 and T3 treatments. Moreover, T2 had high fungi/bacteria (F/B) value, indicating that fungi could benefit the stabilization of paddy soil. In summary, simultaneous nitrogen application (urea or biogas slurry) and straw returning could increase soil microbial activity and improve soil environment in paddy field.The early-spring and autumn-winter tomato in greenhouse is the main planting patterns of protected vegetable in North China. Taking the customary fertilization amount of farmers under this planting pattern as control (CK, 100% chemical fertilizer), six organic fertilizer replacing chemical fertilizer treatments were set, namely, 15% (T1), 30% (T2), 45% (T3), 60% (T4), 75% (T5), 100% organic fertilizer (T6), to examine the replacing effects on soil environment and tomato yield. The results showed that soil bacteria increased with increasing organic fertilizer amount, the actinomycetes wers up to 12.12×106 cfu·g-1 under T1 treatment which was the highest one. Combined application of organic fertilizer could increase soil urease activity, decrease catalase activity, increase soil organic matter, and enhance the concentrations of available phosphorus and available potassium, indicating that organic fertilizer had significant effects on soil physical and chemical properties, soil enzyme activity and nutrient accumulation. The invertase activity and available phosphorus content under T1 treatment were the highest, being 1.36 mg·g-1 and 305.4 mg·kg-1, respectively, while the available potassium content of T2 treatment was the highest (582.6 g·kg-1). In addition, T2 had the largest percentage of >0.25 mm water-stable agglomerate (94.2%). Compared with CK, the application of organic fertilizer could improve tomato quality and increase yield. The lycopene content of T1 was the highest (5.69), the sugar-acid ratio of T1 and T2 was 8.19 and 8.70, respectively, with better tastes. The yield of T1 was the highest, followed by T2 treatment, which was 16.6% and 5.8% higher than that of CK, respectively. It suggested that reducing the application rate of chemical fertilizers by 15%-30% with organic fertilizer was a preferred fertilization measure in this planting pattern.Under Xinjiang winter wheat seeding pattern, in order to sort out proper phosphorus application (PA) and find out the effects and mechanism of PA on population structure, photosynthesis characteristics and yield and provide reliable evidence for PA management of winter wheat, we arranged a two-factor complete split-plot design of wheat variety “Xindong 22”. The main area consisted of two seeding ways drill seeding pattern (D) and uniform seeding pattern (U), while in the sub-area there were four levels of PA(P2O5) 0, 60, 120, and 180 kg·hm-2(represented by P0, P60, P120 and P180 for those treatments, respectively). The results showed that the earbearing percentage in U was 15.9% higher than that in D, and the other features (PAR interception rate, extinction coefficient, leaf area index, SPAD and photosynthetic parameters) were more optimal in 120 kg·hm-2 treatment. Our results showed that the 120 kg·hm-2 treatment in U would be the optimal option with respect to population structure, photosynthetic characteristics, and yield.A completely random split zone experiment with irrigation as main plots and nitrogen application rate as sub-plots was carried out to examine the optimal water-nitrogen coupling mode for oil flax planting in dryland. There were three irrigation levels, no irrigation (0 m3·hm-2, I0), irrigation at 1200 m3·hm-2(I1200) and at 1800 m3·hm-2(I1800); and three nitrogen application rates, no nitrogen (0 kg N·hm-2, N0), 60 kg·N hm-2(N60) and 120 kg·N hm-2(N120). We investigated nitrogen accumulation content at different growth stages, nitrogen transport characteristics after anthesis, grain yield and nitrogen utilization efficiency of oil flax. Results showed that the coupling effects of water and nitrogen application on nitrogen uptake in different organs, nitrogen accumulation during different growth stages and grain yield of dry land oil flax varied greatly. Under no irrigation, nitrogen application was beneficial to stem nitrogen absorption at anthesis and maturity stages, but 120 kg N·hm-2 inhibited it at differeter-nitrogen coupling management mode in this area.Understanding population quality and nitrogen utilization characteristics of direct seeding rice under water-nitrogen interaction could provide theoretical and practical basis for high yield and ample production of direct seeding rice. Hybrid rice F You 498 was used as the material. Three irrigation methods were set in this study flooding irrigation (W1), dry-wet alternate irrigation (W2) and drying irrigation (W3), with different ratio of base fertilizer tiller fertilizer panicle fertilizer at 532 (N1), 334 (N2), 316 (N3), respectively. No nitrogen application (N0) was set as the control. We investigated the effects of water-nitrogen interaction on population quality and nitrogen utilization characteristics of direct seeding rice, with the aim to clarify the relationship between population quality construction, nitrogen utilization characteristics and yield of direct seeding rice. The results showed that irrigation and N rate significantly interacted to affect dry matter accumulation, rice harvest index, heading high-efficiency leaf (the upper three leaves) dry weight, light transmittance rate at maturity stage, total nitrogen accumulation (TNA), apparent nitrogen use efficiency (ANE), nitrogen partial factor productivity (NPFP), nitrogen physiology efficiency, and rice yield.