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1.
Excessive fertilization has led to nutrient use inefficiency and serious environmental consequences for radish cultivation in North China.  The Nutrient Expert (NE) system is a science-based, site-specific fertilization decision support system, but the updated NE system for radish has rarely been evaluated.  This study aims to validate the feasibility of NE for radish fertilization management from agronomic, economic, and environmental perspectives.  A total of 46 field experiments were conducted over four seasons from April 2018 to November 2019 across the major radish growing regions in North China.  The results indicated that NE significantly reduced N, P2O5, and K2O application rates by 98, 110, and 47 kg ha−1 relative to those in the farmers’ practice (FP), respectively, and reduced N and P2O5 inputs by 48 and 44 kg ha−1, respectively, while maintaining the same K2O rate as soil testing (ST).  Relative to FP and ST, NE significantly increased radish yield by 2.7 and 2.6 t ha−1 (4.2 and 4.0%) and net returns by 837 and 432 USD ha−1, respectively.  On average, NE significantly improved the agronomic efficiency (AE) of N, P, and K (relative to FP and ST) by 42.4 and 31.0, 67.4 kg kg−1 and 50.9, and 20.3 and 12.3 kg kg−1; enhanced the recovery efficiency (RE) of N, P, and K by 11.4 and 7.0, 14.1 and 7.5, and 11.3 and 6.3 percentage points; and increased the partial factor productivity (PFP) of N, P, and K by 162.9 and 96.8, 488.0 and 327.3, and 86.9 and 22.4 kg kg−1, respectively.  Furthermore, NE substantially reduced N and P2O5 surpluses by 105.1 and 115.1 kg ha−1, respectively, and decreased apparent N loss by 110.8 kg ha−1 compared to FP.  These results indicated that the NE system is an effective and feasible approach for improving NUE and promoting cleaner radish production in North China.  相似文献   

2.
The rice–crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.  However, its environmental and economic sustainability has not been thoroughly investigated.  This study uses a survey in 2016 and a field experiment in 2017 in Qianjiang, Hubei Province, China to assess the relative economics of concurrent rice–wheat (RW), rice–crayfish (RC), and crayfish monoculture (CM) models in waterlogged land areas.  The field survey indicated that the RC model had a higher benefit–cost ratio (3.5:1) than the RW (2.0:1) and CM (3.1:1) models and the RC model protected farmers’ enthusiasm for grain production facing unfavourable weather conditions.  The field experiment aimed to explore nitrogen management strategies in RC fields.  In the experiment, four levels of nitrogen concentration gradient - 0 kg N ha–1 (0 N), 75 kg N ha–1 (75 N), 150 kg N ha–1 (150 N) and 225 kg N ha–1 (225 N), were set in a 2-year-old rice–crayfish (RC2) field, an 8-year-old rice–crayfish (RC8) field, and a RW field as a control.  The field experiment results suggested that the peak  rice yield in RW, RC2, and RC8 occurred when 225 N, 150 N and 75 N were used, respectively.  In RC2 and RC8, however, residual feed-nitrogen that was not used by crayfish was utilized by rice plants.  Thus, an optimal amount of nitrogen in RC fields was proposed to improve the nitrogen use efficiency and reduce environmental pollution by nitrogen fertilizer.  Farmers use less nitrogen but have higher net income in RC than in RW and CM.  It is necessary to sustainably develop integrated farming technologies (i.e., proper field configurations for rice fields) to effectively sustain rice production.  The results also showed that the RC farming model was a viable diversification option for rice farmers in waterlogged land.    相似文献   

3.
Denitrification-induced nitrogen (N) losses from croplands may be greatly increased by intensive fertilization.  However, the accurate quantification of these losses is still challenging due to insufficient available in situ measurements of soil dinitrogen (N2) emissions.  We carried out two one-week experiments in a maize–wheat cropping system with calcareous soil using the 15N gas-flux (15NGF) method to measure in situ N2 fluxes following urea application.  Applications of 15N-labeled urea (99 atom%, 130–150 kg N ha−1) were followed by irrigation on the 1st, 3rd, and 5th days after fertilization (DAF 1, 3, and 5, respectively).  The detection limits of the soil N2 fluxes were 163–1 565, 81–485, and 54–281 μg N m−2 h−1 for the two-, four-, and six-hour static chamber enclosures, respectively.  The N2 fluxes measured in 120 cases varied between 159 and 2 943 (811 on average) μg N m−2 h−1, which were higher than the detection limits, with the exception of only two cases.  The N2 fluxes at DAF 3 were significantly higher (by nearly 80% (P<0.01)) than those at DAF 1 and 5 in the maize experiment, while there were no significant differences among the irrigation times in the wheat experiment.  The N2 fluxes and the ratios of nitrous oxide (N2O) to the N2O plus N2 fluxes following urea application to maize were approximately 65% and 11 times larger, respectively (P<0.01), than those following urea application to wheat.  Such differences could be mainly attributed to the higher soil water contents, temperatures, and availability of soil N substrates in the maize experiment than in the wheat experiment.  This study suggests that the 15NGF method is sensitive enough to measure in situ N2 fluxes from intensively fertilized croplands with calcareous soils.  相似文献   

4.
Planting under plastic-film mulches is widely used in spring maize production in arid-cold regions for water conservation and warming the soil.To ameliorate the associated issues such as plastic-film residues and additional labor during the“seedling release” in spring maize production, we have developed a plastic-film-side seeding (PSS) technology with the supporting machinery.In the semi-arid regions of Northwest China, a 7-year trial demonstrated that PSS increased plant number per hectare by ...  相似文献   

5.
Utilizing the heterosis of indica/japonica hybrid rice (IJHR) is an effective way to further increase rice grain yield.Rational application of nitrogen (N) fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield potential.However,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain elusive.The purpose of this study was to clarify these issues.Three rice cultivars currently used...  相似文献   

6.
Lodging in maize leads to yield losses worldwide. In this study, we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics, culm mechanical strength, lignin content,root growth, lodging percentage and production in maize at a high plant density. We compared a traditional nitrogen(N) application rate of 300 kg ha–1(R) and an optimized N application rate of 225 kg ha–1(O) under four N application modes: 50% of N applied a...  相似文献   

7.
Crop straw return after harvest is considered an important way to achieve both agronomic and environmental benefits.  However, the appropriate amount of straw to substitute for fertilizer remains unclear.  A field experiment was performed from 2016 to 2018 to explore the effect of different amounts of straw to substitute for fertilizer on soil properties, soil organic carbon (SOC) storage, grain yield, yield components, nitrogen (N) use efficiency, phosphorus (P) use efficiency, N surplus, and P surplus after rice harvesting.  Relative to mineral fertilization alone, straw substitution at 5 t ha–1 improved the number of spikelets per panicle, effective panicle, seed setting rate, 1 000-grain weight, and grain yield, and also increased the aboveground N and P uptake in rice.  Straw substitution exceeding 2.5 t ha–1 increased the soil available N, P, and K concentrations as compared with mineral fertilization, and different amounts of straw substitution improved SOC storage compared with mineral fertilization.  Furthermore, straw substitution at 5 t ha–1 decreased the N surplus and P surplus by up to 68.3 and 28.9%, respectively, compared to mineral fertilization.  Rice aboveground N and P uptake and soil properties together contributed 19.3% to the variation in rice grain yield and yield components.  Straw substitution at 5 t ha–1, an optimal fertilization regime, improved soil properties, SOC storage, grain yield, yield components, N use efficiency (NUE), and P use efficiency (PUE) while simultaneously decreasing the risk of environmental contamination.  相似文献   

8.
[目的]探索适宜云贵高原的玉米花生最佳间作模式并筛选适合该模式的花生品种。[方法]通过随机区组设计,设置6种种植方式,成熟期收获测产,测量数据采用Excel和DPS数据统计分析软件进行分析。[结果]玉米花生间作体系较单作相比,具有明显的间作优势,土地当量比(LER)均大于1。玉米与云花生3号在2﹕2间作模式下LER为1.40,复合产量达到9 036 kg/hm2,玉米与云花生3号在2﹕2间作模式下玉米籽粒、鲜花生荚果及与干花生荚果净产值,分别比玉米单作增加182.63%、140.59%。云花生3号在单作及间作模式下较砚山当地常规种植花生品种相比,其产值分别比砚山当地常规种植花生品种最高可增加5 069、3 272 yuan/hm2。[结论]云贵高原玉米花生间作采用2﹕2间作模式,间作花生品种采用云花生3号,具有最高间作产量及经济效益优势,能最大限度提高土地利用率。  相似文献   

9.
Wheat flour products are the main dietary component of the Qinghai–Tibetan Plateau (QTP) population in China.  However, the high altitude restricts the local wheat quality and quantity, and the applied nitrogen rate is higher than the optimal rate for wheat planting.  In this study, we considered whether reducing the amount of nitrogen fertilizer and introducing the superior varieties from the North China Plain (NCP) are viable ways to increase the wheat quality and quantity in the QTP.  Three and four winter wheat cultivars from QTP and NCP, respectively, were planted in Lhasa at an altitude of 3 647 m with reduced topdressing nitrogen application at the jointing stage.  The wheat from NCP exhibited higher grain hardness index and test weight, and better flour and dough quality.  Reducing the topdressing nitrogen fertilizer from 135 to 75 kg N ha−1 at the jointing stage (with the same basal fertilization of 105 kg N ha−1) did not significantly (P<0.05) affect the grain yield, grain quality, flour quality or dough quality in any of the cultivars.  In summary, introducing high-quality winter wheat varieties from the NCP to the Lhasa plateau is a viable way to enhance the wheat supply and quality in the QTP.  Reducing a certain amount of the nitrogen fertilizer is an economic and feasible approach for the QTP region.  相似文献   

10.
[目的]建立较优的芝麻与花生间作套种的配比及施肥技术。[方法]采用双因素(2种施肥方法和5种配比)随机区组设计,10个处理,3次重复,共30个小区,小区面积12.0m2。2种施肥方法分别为C1[底肥(540g/小区,复合肥+追肥(90g/小区,尿素)]和C2[全部作底肥(540g小区,复合肥)]。五种配比(芝麻:花生)分别为M1(2∶4),M(22∶6),M(31∶4),单作芝麻(CK1),单作花生(CK2)。[结果]6行花生2行芝麻,每小区施底肥540g,复合肥+追肥90g尿素处理,产值和土地当量比(LER)最高,分别为22378.68元/hm2和1.56;芝麻产量641.64kg/hm2、花生产量2506.67kg/hm2;产投比4.94;较单作花生、芝麻收益增加32.32%、95.97%。[结论]该研究可以为找到芝麻与花生的最佳种植配比和合理施肥提供理论依据。  相似文献   

11.
密集烤房不同装烟方式烘烤效果研究   总被引:4,自引:0,他引:4  
为了探寻适合广东烟叶烘烤生产的装烟方式,对梳式烟夹、散叶插签堆放及常规竹竿等3 种装烟方式进 行对比试验。结果表明,与常规竹竿相比,梳式烟夹和散叶插签堆放设备投入成本较高,但这两种装烟方式的装烟量 和装烟密度比常规竹竿大幅增加,装烟和卸烟工作效率明显提高,用工成本显著降低;在烘烤过程的能耗方面,梳式 烟夹和散叶插签堆放较常规竹竿有不同程度的降低,进一步节省烘烤成本;从烤后烟叶经济性状来看,梳式烟夹的 表现最好,常规竹竿和散叶插签堆放次之,因此认为梳式烟夹可进一步试验和推广。  相似文献   

12.
Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei...  相似文献   

13.
为了研究谷子花生不同间作方式对谷子生长发育和产量的影响,选用农大8号和晋花10号为试验材料进行大田试验,设置了谷子单作(T1)、谷子花生2:4间作(T2)、谷子花生3:3间作(T3)、谷子花生4:2间作(T4)、花生单作(T5)共5个处理。结果表明:①与单作相比,间作处理下谷子叶片的净光合速率、蒸腾速率、气孔导度和SPAD值均有不同程度的提高,胞间二氧化碳浓度有所下降。②对于叶绿素荧光参数,间作谷子叶片PSⅡ实际光化学效率、电子传递速率、光化学荧光猝灭系数、PSⅡ潜在光化学活性相比较单作均有显著提高,PSⅡ最大量子产量变化不明显。③对于产量指标来说,间作谷子产量相比较单作得到提升,而由于高位谷子遮阴,导致花生通风透光性较差,抑制了花生的生长发育,使其处于间作劣势,但间作处理总体仍具有明显的间作优势,其中T2处理效果最好。研究结果为间作谷子栽培及高产稳产提供了一定的理论依据。  相似文献   

14.
Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).  Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses, while the performance of drip fertigation in winter wheat is limited by poor N scheduling.  A two-year field experiment was conducted to evaluate the growth, development and yield of drip-fertigated winter wheat under different split urea (46% N, 240 kg ha–1) applications.  The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.  The five N scheduling treatments were N0–100 (0% at sowing and 100% at jointing/booting), N25–75 (25% at sowing and 75% at jointing and booting), N50–50 (50% at sowing and 50% at jointing/booting), N75–25 (75% at sowing and 25 at jointing/booting), and N100–0 (100% at sowing and 0% at jointing/booting).  The SRF (43% N, 240 kg ha–1) was only used as fertilizer at sowing.  Split N application significantly (P<0.05) affected wheat grain yield, yield components, aboveground biomass (ABM), water use efficiency (WUE) and nitrogen partial factor productivity (NPFP).  The N50–50 and SRF treatments respectively had the highest yield (8.84 and 8.85 t ha–1), ABM (20.67 and 20.83 t ha–1), WUE (2.28 and 2.17 kg m–3) and NPFP (36.82 and 36.88 kg kg–1).  This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.  Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading, the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.  相似文献   

15.
The dense and erect panicle (EP) genotype conferred by DEP1 has been widely used in the breeding of high-yield Chinese japonica rice varieties.  However, the breeding value of the EP genotype has rarely been determined at the plant population level.  Therefore, the effects of the interaction of EP genotype and the environment at different locations and times on rice yield and its various components were investigated in this study.  Two sets of near-isogenic lines (NILs) of EP and non-EP (NEP) genotypes with Liaojing 5 (LG5) and Akitakomachi (AKI) backgrounds were grown in the field in 2016 and 2017 in Shenyang, China, and Kyoto, Japan.  In 2018, these sets were grown only in Kyoto, Japan.  The average yields of the EP and NEP genotypes were 6.67 and 6.13 t ha−1 for the AKI background, and 6.66 and 6.58 t ha−1 for the LG5 background, respectively.  The EP genotype positively affected panicle number (PN) and grain number per square meter (GNPM), mostly resulting in a positive effect on harvest index (HI).  In contrast, the EP genotype exerted a negative effect on thousand-grain weight (KGW).  The ratio of the performance of the EP genotype relative to the NEP genotype in terms of yield and total biomass correlated positively with mean daily solar radiation during a 40-day period around heading.  These results indicate that the effectiveness of the EP genotype depends on the availability of solar radiation, and the effect of this genotype is consistently positive for sink formation, conditional in terms of source capacity, and positive in a high-radiation environment.  相似文献   

16.
Malus prunifolia Borkh. ‘Fupingqiuzi’ has significant ecological and economic value and plays a key role in germplasm development and resistance research.  However, its long juvenile phase and high heterozygosity are barriers to the identification of ‘Fupingqiuzi’ progeny with excellent traits.  In-vitro regeneration techniques and Agrobacterium-mediated genetic transformation systems can efficiently produce complete plants and thus enable studies of gene function.  However, optimal regeneration and genetic transformation systems for ‘Fupingqiuzi’ have not yet been developed.  Here, we evaluated the factors that affect the in-vitro regeneration and transformation of ‘Fupingqiuzi’.  The best results were obtained when transverse leaf sections were used as explants, and they were grown in dark culture for three weeks with their adaxial sides contacting the culture medium (MS basal salts, 30 g L−1 sucrose, 8 g L−1 agar, 5 mg L−1  6-benzylaminopurine (6-BA), 2 mg L−1 thidiazuron (TDZ), and 1 mg L−1 1-naphthlcetic acid (NAA), pH 5.8).  A genetic transformation system based on this regeneration system was optimized: after inoculation with A. tumefaciens solution for 8 min, 4 days of co-culture, and 3 days of delayed culture, the cultures were screened with cefotaxime (150 mg L−1) and kanamycin (15 mg L−1).  We thus established an efficient regeneration and genetic transformation system for ‘Fupingqiuzi’, enabling the rapid production of transgenic material.  These findings make a significant contribution to apple biology research  相似文献   

17.
Reducing environmental impacts and improving N utilization are critical to ensuring food security in China.  Although root-zone fertilization has been considered an effective strategy to improve nitrogen use efficiency (NUE), the effect of controlled-release urea (CRU) applied in conjunction with normal urea in this mode is unclear.  Therefore, a 3-year field experiment was conducted using a no-N-added as a control and two fertilization modes (FF, furrow fertilization by manual trenching, i.e., farmer fertilizer practice; HF: root-zone hole fertilization by point broadcast manually) at 210 kg N ha–1 (controlled-release:normal fertilizer=5:5), along with a 1-year in-situ microplot experiment.  Maize yield, NUE and N loss were investigated under different fertilization modes.  The results showed that compared with FF, HF improved the average yield and N recovery efficiency by 8.5 and 22.3% over three years, respectively.  HF had a greater potential for application than FF treatment, which led to increases in dry matter accumulation, total N uptake, SPAD value and LAI.  In addition, HF remarkably enhanced the accumulation of 15N derived from fertilizer by 17.2% compared with FF, which in turn reduced the potential loss of 15N by 43.8%.  HF increased the accumulation of N in the tillage layer of soils at harvest for potential use in the subsequent season relative to FF.  Hence, HF could match the N requirement of summer maize, sustain yield, improve NUE and reduce environmental N loss simultaneously.  Overall, root-zone hole fertilization with blended CRU and normal urea can represent an effective and promising practice to achieve environmental integrity and food security on the North China Plain, which deserves further application and investigation.  相似文献   

18.
The use of nitrogen (N)-efficient rice (Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored.  Here, three japonica N-efficient varieties (NEVs) and three japonica N-inefficient varieties (NIVs) of rice were grown in a paddy field under N omission (0 N, 0 kg N ha–1) and normal N (NN, 180 or 200 kg N ha−1) treatments.  Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency (NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation (PI), as well as higher spikelet–leaf ratio and more productive tillers during the grain-filling stage.  Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho–physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose-1,5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance.  Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation.  These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.  相似文献   

19.
【目的】探究不同种植模式和施氮水平下玉米大豆的叶片持绿、光合和系统产量特性。【方法】通过田间定位试验研究种植方式(玉米单作(MM)、大豆单作(SS)、玉米套作(IM)、大豆套作(IS))和施氮水平(不施氮(NN)、减量施氮(RN:180 kg N·hm-2)、常量施氮(CN:240 kg N·hm-2))对玉米大豆叶片持绿、光合特性以及其干物质积累和系统产量的影响。【结果】玉米产量随施氮量增加而增加,大豆产量随施氮增加先增后降;RN下,IM的籽粒干物质积累量最大,玉米大豆套作系统的总产量最高,系统生产力指数(SPI)最大。套作下各作物的叶片持绿期更长,光合特性指标均较单作稳定,且在籽粒形成期优于单作;各施氮水平下,套作处理的绿叶百分比均显著高于单作,IM的最大绿叶衰减速率出现天数比MM的分别晚7 d、5 d和1 d;IS的则比SS的分别晚7 d、0 d和11 d。相比单作,套作可以显著降低各施氮水平下玉米叶片的平均衰减速率,延长最大衰减速率出现天数,降低绿叶衰减程度。各作物的光合速率表现为套作高于单作,减量施氮高于常量施氮。玉米R2期,IM的叶片光化学淬灭系数(Qp)比MM的高12.78%,非光化学淬灭系数(NPQ)则低21.30%;NPQ随施氮水平的增加而降低,RN比NN降低了17.11%。套作SPAD值波动幅度弱于单作,且呈稳定上升趋势;玉米R2期,IM比MM高34.52%,大豆R2和R6期,IS分别比SS高10.39%、29.48%;RN的SPAD值最高,玉米R2期,IMRN处理比IMNN处理高17.46%,MMRN处理比MMNN处理高35.02%;大豆R6期,ISRN处理比ISNN和ISCN处理分别高7.71%、6.67%,SSRN处理比SSCN处理高10.03%。【结论】减量施氮下,玉米大豆套作显著延长了叶片的持绿期;花后叶片的光合速率、PSⅡ光合机构功能、叶绿素都保持在较高的水平且比单作稳定,籽粒干物质积累增强,充分发挥了玉米的生产潜力并增加了大豆产量,使得套作系统总产量显著提高。  相似文献   

20.
为了研究谷子花生间作下错期播种对谷子农艺性状及产量的影响,本试验以谷子品系'金选6号'为试验材料,设置6个谷子播期处理(分别为T1:5月15日、T2:5月20日、T3:5月25日、T4:5月30日、T5:6月4日、T6:6月9日),花生播种日期为5月15日;通过测定不同处理的谷子农艺性状、产量因素以及产量,研究了谷子花...  相似文献   

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