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A long-term fertilization field experiment was conducted to investigate the effect of nitrogen (N), phosphorus (P), and potassium (K) fertilizer on maize relative yield, yield-increasing effect and the changes of nutrients in yellow soil in Guizhou Province. Five fertilizer combinations were evaluated, including balanced fertilization (NPK) and nutrient deficiency treatments (N, NK, NP, and PK). The maize relative yield, contribution efficiency of N, P, K fertilizer application, sustainability index of soil N, P, K nutrients, and other indicators were measured...

Super hybrid early rice variety Ganxin 203 was used as test material, and four foliar spraying treatments were set using clear water as the control group (CK), and 3 concentrations of potassium dihydrogen phosphate (KH2 PO4 ) with 0.1% (P1), 0.3% (P3), 0.5% (P5) and po-tash (MH). The effects of spraying P and K fertilizers on the leaf temperature, yield and physiolo-gical characteristics in double-season early rice under low temperature conditions during panicle primordium differentiation stage were studied...

The 30-year-old biological soil crusts dominated by mosses (hereafter moss crusts) and corresponding uncrusted soil (hereafter no crust) were sampled on loess soil and aeolian soil at 0-12 cm depth on the Loess Plateau of China. Afterwards, the hydrolase activities of the samples were measured, and their correlations with soil physicochemical properties were analyzed. Compared with no crust, the activities of urease, alkaline phosphatase, invertase, and protease of the moss crusts were 2.4, 7.6, 20.7, 2.4 times higher on loess soil, respectively; while they were 3...

Two grape varieties 'Italia' and 'Centenial seedless' cultured in protected and delayed cultivation were used as experimental materials to study the effects of red and blue light quality on chlorophyll content, net photosynthetic rate, and endogenous hormone content during leaf senescence. The results showed that the chlorophyll content and net photosynthetic rate of the grapes were significantly enhanced in the red light treatment. Although the content of endogenous GA3 was decreased, an increase in abscisic acid (ABA) content and a decrease of total content of zeaxanthin (ZR) were obviously slowed, which led to the significant increase in value of (GA3 +ZR)/ABA, delaying leaf senescence...

Two precocious walnut varieties, Lvling and Lvzao were used as materials in this study, the kernel fat contents and 3 related enzyme activities in different development periods after flowe-ring 50 days were analyzed. The key enzymes affecting walnut fat in different periods were illumina-ted. The results showed that the kernel fat accumulation trends of the two varieties were basically the same. The kernel began to solidify 50 days after flowering, and the increase in kernel fat content was rapid 60-90 days after flowering, slowed down 90-120 days after flowering, and stopped 120-130 days after flowering...

The zinc, boron and molybdenum were sprayed on the foliage of Angelica dahurica du-ring the vigorous growth period to explore the effects of the combination of zinc, boron and molybdenum fertilizers on the content of main effective components of A. dahurica, and to find out the optimum spraying amount. The results showed that the application of zinc, boron and molybdenum foliar spray was beneficial to increase the content of imperatorin and total cumarin, whereas had no effect on the content of the isoimperatorin...

Focused on different rehabilitation ages grassland in Wuqi County in loess hilly region, the present study aimed to explore niche characteristics of populations and their influence factors. The results showed that the dominant species were Artemisia sacrorum, A. leucophylla, A. scoparia, Lespedeza daurica and Poa sphondylodes, and the dominant species varied along with the rehabilitation age. The niche breadth of dominant populations increased with increasing rehabilitation age from 5 to 10 years, indicating enhanced adaptability to the environment...

In Abies fargesii forests of the giant panda's habitats in Mt. Taibai, the spatial distribution patterns and interspecific associations of main tree species and their spatial associations with the understory flowering Fargesia qinlingensis were analyzed at multiple scales by univariate and bivaria-te O-ring function in point pattern analysis. The results showed that in the A. fargesii forest, the number of A. fargesii was largest but its population structure was in decline. The population of Betula platyphylla was relatively young, with a stable population structure, while the population of B...

Thermal dissipation probe (TDP) was used to continuously measure the sap flux density (Fd ) of Pinus tabuliformis and Hippophae rhamnoides individuals in hilly Loess Plateau, from June to October 2015, and the environmental factors, i.e., photosynthetic active radiation (PAR), water vapor pressure deficit (VPD), and soil water content (SWC), were simultaneously monitored to clarify the difference of rainfall utilization between the two tree species in a mixed plantation. Using the methods of a Threshold-delay model, stepwise multiple regression analyses, and partial correlation analyses, this paper studied the process of Fd in these two species in response to the rainfall pulses and then determined the effects of environmental factors on Fd ...

Based on dendrochronological methods, we established residual chronologies of Pinus koraiensis and Picea jezoensis, with the dominant species of broadleaved Korean pine mixed forest at low altitudes chosen as the research object, to identify the key climatic factors affecting the radial growth of the two species in Xiaoxing'anling Mountains, Northeast China. The results showed that the responses of the two species to climate factors were different, and P. koraiensis was more sensitive, and hence more suitable for dendroclimatological analysis...

With the aim to control and reduce rainfall and snowmelt runoff in northern cities in China, the summer runoff and spring snowmelt runoff in the studied area were simulated with the establishment of storm water management model (SWMM). According to the climate characteristics and the situation of the studied area, the low impact development (LID) green ecological strategies suitable for the studied area were established. There were three kinds of management strategies being used, including extended green roof, snow and rainwater harvesting devices, and grass-swales or trenches...

Based on the satellite image in 1984, 2000 and 2016, we analyzed the temporal and spatial variation of cropland requisition-compensation in Changshu City, Jiangsu Province. Based on ArcGIS and the data of soil samples, membership function with integrated fertility index were used to evaluate the soil fertility in 1984 and 2000, respectively. The overlay analysis had been used to reveal the characteristics of soil fertility of cropland requisition-compensation between the period of 1984 to 2000 and 2000 to 2016...

To resolve the problem of higher application and lower use efficiency of phosphorus fertilizer of Chinese cabbage (Brassica pekinensis), the yield, use efficiency of phosphate fertilizer and soil phosphate balance were examined by a located field trial in Zhangye Observation and Experiment Station of the Agro-ecological Environment in oasis irrigation region from 2011 to 2013. The results showed that the yield increased with the increase of phosphorus fertilization rate from 0 to 112.52 kg P·hm-2 , beyond which there would be no further enhancement...

The availability of CO2 , a substrate for photosynthesis, affects the photosynthesis process and photosynthate production. Using the Li-6400-40B, we measured the photosynthetic electron transport rate and the photosynthetic light-response curves of soybean (Glycine max) leaves at different CO2 concentrations (300, 400, 500 and 600 μmol·mol-1 ). By fitting these parameters with a mechanistic model characterizing the light response of photosynthesis, we obtained aseries of photosynthetic parameters, eco-physiological parameters, as well as the physical parameters of photosynthetic pigments...

The elevated concentration of tropospheric ozone (O3 ) is an important global climate change driver, with adverse impacts on soil ecological environment and crop growth. In this study, a pot experiment was carried out in an open top chamber (OTC), to investigate the effects of elevated ozone concentration on soil enzyme activities (catalase, polyphenol oxidase, dehydrogenase and invertase), organic acids contents (oxalic acid, citric acid and malic acid) at different growth stages (tillering, jointing, heading and ripening stages) of wheat, and combined with the rhizospheric soil physicochemical properties and plant root characteristics to analyze the underlying reasons...

With the aim to optimize the structural characteristics of wheat canopy by improving topsoil structure, we examined the effects of three different tillage treatments, deep tillage (DT), shallow tillage (ST), no-tillage (NT) alone, and with application of organic fertilizer, DTF, STF and NTF, on the soil structure and wheat canopy characteristics for five years. Under the same tillage treatment, application of organic fertilizer decreased soil bulk density, the content of soil aggregates with diameter > 5 mm, the mean mass diameter (MWD), and geometric mean diameter (GMD) values of the soil aggregates with diameter >0...

With the large-spike wheat cultivar Shannong 23 as test material,a field experiment was conducted by increasing the relative soil moisture content to 70% and 65% at jointing and anthesis stages. Four nitrogen levels,0 (N0 ), 180 (N1 ), 240 (N2 ) and 300 kg·hm-2 (N3 ), were designed to examine the effects of nitrogen application rates on the interception of photosynthetic active radiation (PAR) and dry matter distribution of wheat at different canopy layers. The results showed that the total stem number of wheat population at anthesis stage, the leaf area index at 10, 20 and 30 days after anthesis, PAR capture ratio at upper and middle layers and total PAR capture ratio in wheat canopy on day 20 after anthesis of treatment N2 were significantly higher than those in the treatments of both N0 and N1 ...

To explore the effects of different nitrate nitrogen levels (N0 , N1 , N2 , N3 and N4 were equivalent to 0, 2.5, 5, 10, 20 mmol·L-1 15 NO3 - -N, respectively) on the growth, photosynthetic characteristics and 15 N absorption, utilization and distribution, Malus hupehensis seedlings were grown in cultural liquid Hoagland by using the 15 N-labeled tracer method. The results showed that the leaf chlorophyll content, leaf area and dry mass in different organs were the highest in N2 treatment. With the increase of 15 NO3 - -N application rates, the leaf net photosynthetic rate (Pn )significantly increased but tended to decease when the 15 NO3 - -N concentration exceeded N2 treatment...

The increasing stocking density of algal often results in lowered carbon and light levels. In this study, Pyropia haitanensis were cultured under four different conditions, i.e., 390 μL·L-1 (ambient carbon supply) + ambient sunlight, 20 μL·L-1 (decreased carbon supply) + ambient sunlight, 390 μL·L-1 + decreased sunlight (20% of ambient sunlight), 20 μL·L-1 + decreased sunlight. The activity of carbonic anhydrase (CA), photosynthetic rate and quantum efficiency of open photosynthetic system 2 (Fv '/Fm ') of the algae under different temperatures were measured to investigate the effects of decreased carbon supply and lowered light on photosynthetic functions of P...

The aim of this study was to examine the impacts of characteristics of the shrub (shrub height, shrub width on the windward side, shrub length on the downwind side) on the snow morphology (snow height, snow width, and snow tail length) in the typical steppe of Xilinhot, China. The relationship between shrub height and parameters of snow morphology showed significant quadratic polynomial regression. The relationship between shrub width on the windward side, length on the downwind side and parameters of snow morphology showed significant power function (exponent was less than 1)...