Macleanpilegaard3091

Under the W2 treatment, the RV decrease of L22 was 26.2% lower than that of L17, and CAT, POD, SOD activities and the thickness of cortex were 43.6%, 6.9%, 25.4%, 19.9% higher than that of L17. There were positive correlations between dry mass and RV, SOD, POD, the number of cork layers, the diameter and number of rhizome ducts. Therefore, cotton variety with strong drought tolerance could maintain higher root activity, cork layer number, the diameter of rhizome ducts, and number under drought conditions, and thus promote the accumulation of aboveground biomass, which was the physiological mechanism for their stronger drought tolerance.Two-year field experiments were conducted in 2017-2018 to examine the effects of wheat straw returning and fertilization on soil fertility and enzyme activities, as well as the yield and qua-lity of edible sweetpoato. There were five treatments, including conventional fertilization+zero straw (CK), conventional fertilization+50% straw returning (50%S), zero fertilization+100% straw returning (100%S-F), conventional fertilization+100% straw returning (100%S), conventional fertilization+100% straw retuning+150 kg N·hm-2 (100%S+N). The treatments of straw returning and fertilization significantly increased the contents of available phosphorus (P), hydroly-zable nitrogen (N), total N, and organic matter in soils, and increased the activities of soil catalase, alkaline phosphorylase, urease, and invertase. The storage root yield, single root fresh weight and commodity potato rate were significantly increased under the treatments of straw returning and fertilization. The storage root yield was the lowest under the treatment of 50%S. After two years of straw returning, storage root yield and commodity potato rate were the highest under the treatment of 100%S. In general, the contents of starch and protein in sweetpotato were increased after two years of straw returning and fertilization, but the contents of reducing sugar and soluble sugar were decreased under 100%S and 100%S+N treatments. Our results suggested that straw returning in full quantity was better than straw returning in half quantity. The storage root yield and commodity potato rate was the highest under the combination of full quantity straw returning and conventional fertilization, with the taste of sweetpotato being changed. Thus, the amount of nitrogen fertilizer should be appropriately reduced in actual practice.Light shortage in the canopy of summer maize resulted from the decrease of solar radiation and the increase of planting density in Huanghuaihai region could reduce maize yield. In order to explore the effects of phytase Q9 on leaf senescence characteristics of summer maize, three sha-ding treatments with summer maize hybrid 'Denghai 605' (DH605) were conducted, including shading at flowering to maturity stage (S1), shading at ear stage (S2), and shading at whole growth stage (S3) with natural lighting in the field as control (CK). Chemical control reagent phytase Q9 was used to regulate the shading treatments (the original solution was diluted by 100 times) and the CK exogenously, namely shading at flowering to maturity stage-phytase Q9 (S1Q), shading at ear stage-phytase Q9 (S2Q), and shading at whole growth stage-phytase Q9 (S3Q), and natural lighting-phytase Q9 (CKQ), with spraying water at the same stage as the control. The results showed that leaf area index (LAI), soil-plant analysis development (SPAD) escence.The aims of this study were to reveal the effects of biochar application combined with nitrogen fertilizer on soil physicochemical properties and crop yield in the typical ancient region of Yellow River, and to clarify the dynamics of carbon and nitrogen content and soil physicochemical properties with different treatments of biochar and nitrogen, which could provide scientific basis for reasonable fertilization of soil, quality improvement of cultivated land, and yield increase of winter wheat. A two-year field experiment was conducted with different biochar applications (0, 15, 30 t·hm-2) combined with different nitrogen levels (N 270, 330 kg·hm-2) to investigate their effects on soil physicochemical property in the typical ancient of Yellow River. AMG PERK 44 After 2-yr biochar application, the generalized soil structure index (GSSI) was increased and three-phase structure distance index of soil (STPSD) was decreased, and three-phase ratio was significantly improved. The most ideal state of three-phase ratio was in thr than that with conventional nitrogen application. In summary, combined biochar and nitrogen application could improve soil micro-environment, soil fertility and crop yield. Comprehensively considering soil modification, crop yield improvement and input cost, the optimum amount of fertilization was biochar application (30 t·hm-2) combined with nitrogen fertilizer (330 kg·hm-2).Understanding the dynamics of phosphate-solubilizing and N2-fixing bacteria on soil nutrient and related enzyme activity under different organic fertilizer proportions (OFP) could provide references for screening appropriate inoculant type, OFP, and fertilization period. Here, we set four OFP levels (mass ratio 0%, 4%, 8%, 12%) and inoculated two phosphate-solubilizing bacteria (Bacillus megaterium, Pseudomonas fluorescens) and two N2-fixing bacteria (Azotobacter chroococcum, Azospirillum brasilence) in the subtropical yellow-brown barren soil. After a 60-day soil incubation under controlled conditions (28 ℃, darkness), we examined the impacts of single/mixed applications of beneficial bacteria on soil available nutrients and related enzyme activities at different OFP levels and different sampling times (3rd, 8th, 16th, 30th, 45th, 60th day). The results showed that soil available nutrient contents increased with the elevated OFP levels, and exhibited as 12%>8%>4%>0%. With the extension of culture time, soil ent effect on nitrogen fixation. Soil nutrient contents were positively correlated with enzyme activity, which was affected by both cultural time and carbon-nitrogen ratio. Bacterial inoculations could significantly increase nutrient contents in the short term, but the specific functions of beneficial bacteria on soil were highly dependent on organic carbon input and carbon-nitrogen ratio. Coupled application of inoculants and organic fertilizer at an appropriate OFP level (8%-12%) could increase and extend the soil-remediating effects, while the inoculation should be conducted with an interval of 45-60 days to ensure the survival rate and the consecutive effect on soil.