首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation. One-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE). A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha–1 (named F0, SF225, SF270, SF315, SF360, and SF405) and 405 kg N ha–1 of common fertilizer (CF405) on the grain yield, biomass and N accumulation, enzymatic activities related with carbon–nitrogen metabolism, NUE and economic analysis. Results indicated that the highest grain yields, NUEs and economic returns were achieved at SF360 in both varieties. The enzymatic activities related with carbon–nitrogen metabolism, pre- and post-silking accumulation of biomass and N increased with increasing SF rate, and they were the highest at SF360 and SF405. The grain yield at SF360 had no significant difference with that at SF405. However, the N partial factor productivity, N agronomic efficiency and N recovery efficiency at SF360 were 9.8, 6.6 and 8.9% higher than that at SF405. The results also indicated that the average grain yields, NUE and economic benefit at SF405 were 5.2, 12.3 and 18.1% higher than that at CF405. In conclusion, decreasing N rate from 405 kg ha–1 (CF) to 360 kg ha–1 (SF) could effectively reduce the yield gap between realized and potential maize yields. The N decreased by 11.1%, but the yield, NUE and economic benefit increased by 3.2, 22.2 and 17.5%, which created a simple, efficient and business-friendly system for spring maize production in Jiangsu Province, China.  相似文献   

2.
The objective of this study was to evaluate the effects of organic and inorganic fertilizers on yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore a field trial was carried out at New Developmental Farm of The University Agriculture, Peshawar, Pakistan during winter 2012–13. The field experiment was layout in randomized complete block design with split plot arrangement having three replications. Fertilizers treatments (control, higo organic plus (composted manure, it contains N 2%, P 3%, K 3%, organic matter 40%, organic carbon 11%, Zn 145 mg kg–1, Cu 56 mg kg–1, Fe 380 mg kg–1 and Mg 228 mg kg–1), maxicrop sea gold (extract of sea weeds i.e., Sargasssum, Laminara Polysaccharide and Ascophyllum Nodosum), farm yard manure, NP (90: 60 kg ha–1), NP (120: 90 kg ha–1) and NP (150: 120 kg ha–1) were allotted to main plots while genotypes (Sandrina, Serenada and Kawe Terma) to the sub plots. Farm yard manure (10 t ha–1) and higo organic Plus (5 t ha–1) was incorporated in the soil before seed bed preparation. Maxicrop sea gold (5 lit ha–1) was sprayed after the emergence of the crop. All phosphorus was applied @ of 60, 90 and 120 kg ha–1 at the time of sowing while nitrogen @ of 90, 120 and 150 kg ha–1 in two splits/3 of the dose was applied at the time of sowing while the remaing 1/3 of the dose was applied before earthen up. Plots treated with application of NP ratio 120: 90 kg ha–1 produced maximum beet yield (76.4 t ha–1), sugar yield (11.1 t ha–1), Pol (polarizable sugar) percentage (14.67%) and more economic return (Rs.234 Thousand ha–1) as compared to control plots. Sugar beet genotype Serenada had significantly produced maximum beet yield (55.5 t ha–1), sugar yield (7.9 t ha–1), pol (polarizable sugar) percentage (14.60%), brix percentage (14.60%) and more economic return (158) as compared to other genotypes. It was concluded from the above results that sugar beet genotype Serenada treated with NP ratio 120: 90 kg ha–1 for improved sugar beet productivity and quality therefore it is recommended for general practice in agro-climatic conditions of Peshawar valley.  相似文献   

3.
Wheat was the first crop grown in Egypt, and it remains highly important. Egypt is the largest wheat importer in the world and consumes an extensive amount of bread. It is imperative for wheat scientists to decrease the large gap between production and consumption. Wheat yields in Egypt increased 5.8-fold(6.7 billion kg) between 1961 and 2017 due to variety improvement and the use of better planting methods such as the raised bed method, ideal sowing date, surge flow irrigation and farm irrigation systems, laser levelling, fertilizers, and intercropping with raised beds. In this paper, the development of wheat production techniques and variety evolution over more than five decades in Egypt have been analyzed. In particular, we have focused on the technologies, cultural practices and causes for per unit area yield increase. The main purpose was to study the issues that have arisen during wheat production and to make recommendations for smart agricultural practices. In 1981, the yield was 3 300 kg ha–1 and through the improvement of varieties, expansion of agricultural land and the adoption of modern agricultural techniques yield reached 6 500 kg ha–1 by 2017. The production growth rate was 4.1% annually, and the total grain yield increased 4.3-fold, from 1.9 billion kg in 1981 to about 8.1 billion kg in 2017. The use of new improved varieties, new cultivation techniques, and modern irrigation techniques contributed to 97.0% of the increase in yield per unit area and 1.5% of the increase in yield was due to planting area expansion. Therefore, the increase in total yield mainly depended on the increase in yield per unit area. Wheat production in Egypt has been improved through the development of breeding and cultivation techniques. The use of these new techniques, the popularization of new high-quality seed varieties, and the use of the raised bed method instead of the old method of planting in basins have made the largest contributions to increased yield. In the future, wheat yield could be further increased by using the tridimensional uniform sowing mode and the development of wheat varieties that are resistant to rusts, deficit irrigation, and abiotic stress, that are highly adaptable to mechanized operation and have high yields. Based on our analysis, we propose the main technical requirements and measures to increase wheat yield in Egypt in the near future.  相似文献   

4.
Understanding of how combinations of agronomic options can be used to improve the grain yield and nitrogen use efficiency(NUE) of winter wheat is limited. A three-year experiment involving four integrated management strategies was conducted from 2013 to 2015 in Tai'an, Shandong Province, China, to evaluate changes in grain yield and NUE. The integrated management treatments were as follows: current practice(T1); improvement of current practice(T2); high-yield management(T3), which aimed to maximize grain yield regardless of the cost of resource inputs; and integrated soil and crop system management(T4) with a higher seeding rate, delayed sowing date, and optimized nutrient management. Seeding rates increased by 75 seeds m~(–2) with each treatment from T1(225 seeds m~(–2)) to T4(450 seeds m~(–2)). The sowing dates were delayed from T1(5 th Oct.) to T2 and T3(8 th Oct.), and to T4 treatment(12 th Oct.). T1, T2, T3, and T4 received 315, 210, 315, and 240 kg N ha~(–1), 120, 90, 210 and 120 kg P_2O_5 ha~(–1), 30, 75, 90, and 45 kg K_2O ha~(–1), respectively. The ratio of basal application to topdressing for T1, T2, T3, and T4 was 6:4, 5:5, 4:6, and 4:6, respectively, with the N topdressing applied at regreening for T1 and at jointing stage for T2, T3, and T4. The P fertilizers in all treatments were applied as basal fertilizer. The K fertilizer for T1 and T2 was applied as basal fertilizer while the ratio of basal application to topdressing(at jointing stage) of K fertilizer for both T3 and T4 was 6:4. T1, T2, T3, and T4 were irrigated five, four, four and three times, respectively. Treatment T3 produced the highest grain yield among all treatments over three years and the average yield was 9 277.96 kg ha~(–1). Grain yield averaged across three years with the T4 treatment(8 892.93 kg ha~(–1)) was 95.85% of that with T3 and was 21.72 and 6.10% higher than that with T1(7 305.95 kg ha~(–1)) and T2(8 381.41 kg ha~(–1)), respectively. Treatment T2 produced the highest NUE of all the integrated treatments. The NUE with T4 was 95.36% of that with T2 and was 51.91 and 25.62% higher than that with T1 and T3, respectively. The N uptake efficiency(UPE) averaged across three years with T4 was 50.75 and 16.62% higher than that with T1and T3, respectively. The N utilization efficiency(UTE) averaged across three years with T4 was 7.74% higher than that with T3. The increased UPE with T4 compared with T3 could be attributed mostly to the lower available N in T4, while the increased UTE with T4 was mainly due to the highest N harvest index and low grain N concentration, which consequently led to improved NUE. The net profit for T4 was the highest among four treatments and was 174.94, 22.27, and 28.10% higher than that for T1, T2, and T3, respectively. Therefore, the T4 treatment should be a recommendable management strategy to obtain high grain yield, high NUE, and high economic benefits in the target region, although further improvements of NUE are required.  相似文献   

5.
Improving radiation use efficiency(RUE) of the canopy is necessary to increase wheat(Triticum aestivum) production. Tridimensional uniform sowing(U) technology has previously been used to construct a uniformly distributed population structure that increases RUE. In this study, we used tridimensional uniform sowing to create a wheat canopy within which light was spread evenly to increase RUE. This study was done during 2014–2016 in the Shunyi District, Beijing, China. The soil type was sandy loam. Wheat was grown in two sowing patterns:(1) tridimensional uniform sowing(U);(2) conventional drilling(D). Four planting densities were used: 1.8, 2.7, 3.6, and 4.5 million plants ha–1. Several indices were measured to compare the wheat canopies: photosynthetic active radiation intercepted by the canopy(IPAR), leaf area index(LAI), leaf mass per unit area(LMA), canopy extinction coefficient(K), and RUE. In two sowing patterns, the K values decreased with increasing planting density, but the K values of U were lower than that of D. LMA and IPAR were higher for U than for D, whereas LAI was nearly the same for both sowing patterns. IPAR and LAI increased with increasing density under the same sowing pattern. However, the difference in IPAR and LAI between the 3.6 and 4.5 million plants ha–1 treatments was not significant for both sowing patterns. Therefore, LAI within the same planting density was not affected by sowing pattern. RUE was the largest for the U mode with a planting density of 3.6 million plants ha–1 treatment. For the D sowing pattern, the lowest planting density(1.8 million plants ha–1) resulted in the highest yield. Light radiation interception was minimal for the D mode with a planting density of 1.8 million plants ha–1 treatment, but the highest RUE and highest yield were observed under this condition. For the U sowing pattern, IPAR increased with increasing planting density, but yield and RUE were the highest with a planting density of 3.6 million plants ha–1. These results indicated that the optimal planting density for improving the canopy light environment differed between the sowing patterns. The effect of sowing pattern×planting density interaction on grain yield, yield components, RUE, IPAR, and LMA was significant(P0.05). Correlation analysis indicated that there is a positive significant correlation between grain yield and RUE(r=0.880, P0.01), LMA(r=0.613, P0.05), and spike number(r=0.624, P0.05). These results demonstrated that the tridimensional uniform sowing technique, particularly at a planting density of 3.6 million plants ha–1, can effectively increase light interception and utilization and unit leaf area. This leads to the production of more photosynthetic products that in turn lead to significantly increased spike number(P0.05), kernel number, grain weight, and an overall increase in yield.  相似文献   

6.
A field experiment was conducted on silty clay loam soil in the years 2011–2012. Two sesame (Sesamum indicum L.) cultivars (Local Black and Local White) were evaluated using various 3 different sowing dates (20th June, 10th and 30th July) and four agrotechnical level (0, 40, 80 and 120 kg N ha–1) at New Developmental Farm The University of Agriculture, Peshawar, Pakistan. The objective of this study was to evaluate the effects of sowing dates on growth, yield and oil fatty acid composition of two sesame cultivars grown under different nitrogen fertilization. Results showed that cv. Local Black was characterized by significantly higher content of oil (47%), seed yield (696 kg ha–1) and oil yield (335 kg ha–1) while cv. Local White had higher palmitic acid (8%) and linoleic acid (38.7%). Yield and its main components were positively affected by the earlier sowing date. With regard to fatty acid composition, a decrease in oleic and stearic acid and an increase in linoleic and palmitic acid were observed. At early sowing, oleic and palmitic acid decreased whereas linoleic and stearic acid increased. The decrease in the oleic/linoleic acid ratio observed at early sowing, suggests a possible role of temperature on the activity of oleate desaturase in the developing seeds. Intensive technology of cultivation (120 kg N ha–1), compared to the economical technology (40 kg N ha–1), significantly increased the seed yield of both sesame cultivars. This was due to higher number of branches, Capsules m–2, capsules plant–1, seeds capsule–1 and 1000 seed weight (g). The intensive technology of cultivation had a beneficial effect on the content of palmitic acid, linolenic acid and oleic acid in sesame seed.  相似文献   

7.
Improving both grain yield and resource use efficiencies simultaneously is a major challenge in rice production. However, few studies have focused on integrating dense planting with delayed and reduced nitrogen application to enhance grain yield, nitrogen use efficiency (NUE) and radiation use efficiency (RUE) in rice (Oryza sativa L.) in the double rice cropping system in South China. A high-yielding indica hybrid rice cultivar (Yliangyou 143) was grown in field experiments in Guangxi, South China, with three cultivation managements: farmers’ practice (FP), dense planting with equal N input and delayed N application (DPEN) and dense planting with reduced N input and delayed N application (DPRN). The grain yields of DPRN reached 10.6 and 9.78 t ha–1 in the early and late cropping seasons, respectively, which were significantly higher than the corresponding yields of FP by 23.9–29.9%. The grain yields in DPEN and DPRN were comparable. NUE in DPRN reached 65.2–72.9 kg kg–1, which was 61.2–74.1% higher than that in FP and 24.6–30.2% higher than that in DPEN. RUE in DPRN achieved 1.60–1.80 g MJ–1, which was 28.6–37.9% higher than that in FP. The productive tiller percentage in DPRN was 7.9–36.2% higher than that in DPEN. Increases in crop growth rate, leaf area duration, N uptake from panicle initiation to heading and enhancement of the apparent transformation ratio of dry weight from stems and leaf sheaths to panicles all contributed to higher grain yield and higher resource use efficiencies in DPRN. Correlation analysis revealed that the agronomic and physiological traits mentioned above were significantly and positively correlated with grain yield. Comparison trials carried out in Guangdong in 2018 and 2019 also showed that DPRN performed better than DPEN. We conclude that DPRN is a feasible approach for simultaneously increasing grain yield, NUE and RUE in the double rice cropping system in South China.  相似文献   

8.
《农业科学学报》2023,22(7):2221-2232
Fertilization is an effective technique to improve soil fertility and increase crop yield. The long-term effects of different fertilizers on soil considerably vary. Over 38 consecutive years of different fertilization positioning experiments in a double cropping rice field of Qiyang Red Soil Experimental Station, seven different fertilization treatments including CK (no fertilization), NPK (nitrogen, phosphorus, and potassium fertilizer), M (cow manure), NPKM (nitrogen, phosphorus, and potassium with cow manure), NPM (nitrogen and phosphorus with cow manure), NKM (nitrogen and potassium with cow manure), and PKM (phosphorus and potassium with cow manure) were applied to study the effects on rice yield, soil fertility, and nutrient apparent balance in a paddy field. The results showed that the annual average yields of rice in NPKM, NPM, NKM, PKM, M, NPK and CK treatments ranged from 6 214 to 11 562 kg ha–1. Yields under long-term organic and inorganic treatments (NPKM, NPM, NKM and PKM) were 22.58, 15.35, 10.53 and 4.41%, respectively, greater than under the NPK treatment. Soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN) and available potassium (AK) concentration with long-term organic and inorganic treatment (NPKM, NPM, NKM and PKM) were significantly higher than in inorganic fertilizer (NPK) treatments. Soil total phosphorus (TP) and available phosphorus (AP) contentration with organic fertilizer combined with inorganic N and P fertilizer treatment (NPKM, NPM and PKM) were significantly higher than with inorganic fertilizer alone (NPK treatments). The average annual rice yield (11 562 kg ha–1), SOC (20.88 g kg–1), TN (2.30 g kg–1), TP (0.95 g kg–1), TK (22.50 g kg–1) and AP (38.94 mg kg–1) concentrations were the highest in the NPKM treatment. The soil AN concentration (152.40 mg kg–1) and AK contentration (151.00 mg kg–1) were the highest in the NKM treatment. N and P application led to a surplus of nitrogen and phosphorus in the soil, but NPKM treatment effectively reduced the surplus compared with other treatments. Soils under all treatments were deficient in potassium. Correlation analysis showed that SOC, TN, AN, TP, and AP contentration was significantly correlated with rice yield; the correlation coefficients were 0.428, 0.496, 0.518, 0.501, and 0.438, respectively. This study showed that the combined application of N, P, and K with cow manure had important effects on rice yield and soil fertility, but balanced application of N, P, and K with cow manure was required.  相似文献   

9.
The concentration of soil Olsen-P is rapidly increasing in many parts of China, where P budget(P input minus P output) is the main factor influencing soil Olsen-P. Understanding the relationship between soil Olsen-P and P budget is useful in estimating soil Olsen-P content and conducting P management strategies. To address this, a long-term experiment(1991–2011) was performed on a fluvo-aquic soil in Beijing, China, where seven fertilization treatments were used to study the response of soil Olsen-P to P budget. The results showed that the relationship between the decrease in soil Olsen-P and P deficit could be simulated by a simple linear model. In treatments without P fertilization(CK, N, and NK), soil Olsen-P decreased by 2.4, 1.9, and 1.4 mg kg~(–1) for every 100 kg ha~(–1) of P deficit, respectively. Under conditions of P addition, the relationship between the increase in soil Olsen-P and P surplus could be divided into two stages. When P surplus was lower than the range of 729–884 kg ha~(–1), soil Olsen-P fluctuated over the course of the experimental period with chemical fertilizers(NP and NPK), and increased by 5.0 and 2.0 mg kg~(–1), respectively, when treated with chemical fertilizers combined with manure(NPKM and 1.5 NPKM) for every 100 kg ha~(–1) of P surplus. When P surplus was higher than the range of 729–884 kg ha~(–1), soil Olsen-P increased by 49.0 and 37.0 mg kg~(–1) in NPKM and 1.5 NPKM treatments, respectively, for every 100 kg ha~(–1) P surplus. The relationship between the increase in soil Olsen-P and P surplus could be simulated by two-segment linear models. The cumulative P budget at the turning point was defined as the "storage threshold" of a fluvo-aquic soil in Beijing, and the storage thresholds under NPKM and 1.5 NPKM were 729 and 884 kg ha~(–1)P for more adsorption sites. According to the critical soil P values(CPVs) and the relationship between soil Olsen-P and P budget, the quantity of P fertilizers for winter wheat could be increased and that of summer maize could be decreased based on the results of treatments in chemical fertilization. Additionally, when chemical fertilizers are combined with manures(NPKM and 1.5 NPKM), it could take approximately 9–11 years for soil Olsen-P to decrease to the critical soil P values of crops grown in the absence of P fertilizer.  相似文献   

10.
Now,lodging is a major constraint factor contributing to yield loss of maize (Zea mays L.) under high planting density.Chemical regulation and nitrogen fertilizer could effectively coordinate the relationship between stem lodging and maize yield,which significantly reduce lodging and improve the grain yield.The purpose of this study was to explore the effects of chemical regulation and different nitrogen application rates on lodging characteristics,grain filling and yield of maize under high density.For this,we established a field study during 2017 and 2018 growing seasons,with three nitrogen levels of N100 (100 kg ha~(–1)),N200 (200 kg ha~(–1)) and N300 (300 kg ha~(–1)) at high planting density (90 000 plants ha~(–1)),and applied plant growth regulator (Yuhuangjin,the mixture of 3% DTA-6 and 27% ethephon) at the 7th leaf.The results showed that chemical control increased the activities of phenylalanine ammonia-lyase (PAL),tyrosine ammonia-lyase (TAL),4-coumarate:Co A ligase (4CL),and cinnamyl alcohol dehydrogenase (CAD),and increased the lignin,cellulose and hemicellulose contents at the bottom of the 3rd internode,which significantly reduced the lodging percentage.The lignin-related enzyme activities,lignin,cellulose and hemicellulose contents decreased with the increase of nitrogen fertilizer,which significantly increased the lodging percentage.The 200 kg ha~(–1) nitrogen application and chemical control increased the number,diameter,angle,volume,and dry weight of brace roots.The 200 kg ha~(–1) nitrogen application and chemical control significantly increased the activities of ADP-glucose pyrophosphorylase (AGPase),soluble starch synthase (SSS) and starch branching enzyme(SBE),which promoted the starch accumulation in grains.Additional,improved the maximum grain filling rate (V_(max)) and mean grain filling rate (V_m),which promoted the grain filling process,significantly increased grain weight and grain number per ear,thus increased the final yield.  相似文献   

11.
This paper investigates the yield and nitrogen use efficiency (NUE) of machine-transplanted rice cultivated using mechanized deep placement of N fertilizer in the rice–wheat rotation region of Chuanxi Plain, China. It provides theoretical support for N-saving and improves quality and production efficiency of machine-transplanted rice. Using a single-factor complete randomized block design in field experiments in 2018 and 2019, seven N-fertilization treatments were applied, with the fertilizer being surface broadcast and/or mechanically placed beside the seedlings at (5.5±0.5) cm soil depth when transplanting. The treatments were: N0, no N fertilizer; U1, 180 kg N ha–1 as urea, surface broadcast manually before transplanting; U2, 108 kg N ha–1 as urea, surface broadcast manually before transplanting, and 72 kg N ha–1 as urea surface broadcast manually on the 10th d after transplanting, which is not only the local common fertilization method, but also the reference treatment; UD, 180 kg N ha–1 as urea, mechanically deep-placed when transplanting; M1, 81.6 kg N ha–1 as urea and 38.4 kg N ha–1 as controlled-release urea (CRU), mechanically deep-placed when transplanting; M2, 102 kg N ha–1 as urea and 48 kg N ha–1 as CRU, mechanically deep-placed when transplanting; M3, 122.4 kg N ha–1 as urea and 57.6 kg N ha–1 as CRU, mechanically deep-placed when transplanting. The effects of the N fertilizer treatments on rice yield and NUE were consistent in the 2 yr. With a N application rate of 180 kg ha–1, compared with U2, the N recovery efficiency (NRE), N agronomic use efficiency (NAE) and yield under the UD treatment were 20.6, 3.5 and 1.1% higher in 2018, and 4.6, 1.7 and 1.2% higher in 2019, respectively. Compared with urea alone (U1, U2 or UD), the NRE, NAE and yield achieved by M3 (combined application of urea and controlled-release urea) were higher by 9.2–73.3%, 18.6–61.5% and 6.5–16.5% (2018), and 22.2–65.2%, 25.6–75.0% and 5.9–13.9% (2019), respectively. Compared with M3, the lower-N treatments M1 and M2 significantly increased NRE by 4.0–7.8% in 2018 and 3.1–4.3% in 2019, respectively. Compared with urea surface application (U1 or U2), the yield under the M2 treatment was higher by 4.3–12.9% in 2018 and 3.6–10.1% in 2019, respectively. Compared with U2, the NRE and NAE under the M2 treatment was higher by 36.9 and 36.3% in 2018, and 33.2 and 37.4% in 2019, mainly because of higher N uptake. There was no significant difference in the concentration of nitrate in the top 0–20 cm soil under U1, U2 and M2 treatments during the full heading and maturity stages. During the full heading stage, U2 produced the highest concentration of nitrite in 0–20 cm and 20–40 cm soil among the N fertilizer treatments. In conclusion, mechanized deep placement of mixed urea and controlled-release urea (M2) at transplanting is a highly-efficient cultivation technology that enables increased yield of machine-transplanted rice and improved NUE, while reducing the amount of N-fertilization applied.  相似文献   

12.
Nitrogen fertilizer application is an important measure to obtain high and stable corn yield, and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting. In this study, four different nitrogen fertilizer treatments from 0 to 450 kg ha~(–1) pure nitrogen were set for a planting density of 12.0×10~4 plants ha~(–1) in 2017 and 2018, and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha~(–1) pure nitrogen were set for planting densities of 7.5×10~4 and 12.0×10~4 plants ha~(–1) in 2019, to investigate the effect of nitrogen application rate on the moisture content of corn grains. Under each treatment, the growth of corn, leaf area index(LAI) of green leaves, grain moisture content, and grain dehydration rate were measured. The results showed that, as nitrogen application increased from 0 to 765 kg ha~(–1), the silking stage was delayed by about 1 day, the maturity stage was delayed by about 1–2 days, and the number of physiologically mature green leaves and LAI increased. At and after physiological maturity, the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%. As the amount of nitrogen application increased, the corn grain dehydration rate after physiological maturity decreased, but it did not reach statistical significance between nitrogen application rate and grain dehydration rate. No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity. In short, nitrogen application affected the grain moisture content of corn at and after physiological maturity, however, the difference in grain moisture content among different nitrogen application rates was small. These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production.  相似文献   

13.
氮高效利用基因型大麦氮素转移及氮形态组分特征   总被引：1，自引：0，他引：1  
【目的】揭示氮高效利用基因型大麦生育后期氮素分配转运的生理机制,为大麦高效氮肥管理和高产栽培提供理论依据。【方法】采用土培盆栽试验,利用前期筛选出的氮高效利用基因型大麦（DH61、DH121+）和低效利用基因型大麦（DH80）为试验材料,分析其在不施氮、低氮（125 mgN·kg-1土）、正常氮（250 mgN·kg-1土）和高氮（375 mgN·kg-1土）4个氮素处理下籽粒产量、生物量及生育后期地上部营养体氮素转移特性和植株氮形态组分构成特征。【结果】（1）随施氮量的减少,不同氮效率基因型大麦籽粒产量和地上部生物量均减少。同一施氮处理,高效基因型大麦籽粒产量和地上部生物量高于低效基因型。不施氮处理下,高效型大麦DH61和DH121+籽粒产量分别是低效型DH80的1.96、2.03倍;低氮处理下分别是低效型DH80的2.10、2.37倍。扬花期和灌浆期,不施氮和低氮处理下两类基因型大麦植株氮浓度无明显差异,氮高效基因型大麦干物质形成能力较强。（2）高效基因型大麦植株能够积累较多的氮素,扬花前高效基因型氮素积累量占大麦生育期氮积累量的比例高于低效基因型。低氮（125 mgN·kg-1土）、正常氮（250 mgN·kg-1土）、高氮处理（375 mgN·kg-1土）下,高效基因花前氮素积累量是低效基因型的1.31、1.38、1.49倍,充足的氮素积累为后期灌浆结实奠定了物质基础。（3）随着氮素用量的增加,氮素转运量呈单峰曲线变化,氮素转移率和氮素转运量对籽粒的贡献率则逐渐下降,过高的氮肥施用不利于氮素向籽粒的转运。高效基因型DH61和DH121+籽粒氮素来源更多依赖于前期地上部营养体的氮素转移,不施氮和低氮氮素转运量对籽粒的贡献率分别为35.06%、40.06%和76.37%、81.72%。而低效基因型DH80籽粒的氮素来源则以后期根系氮素的吸收和转移为主,氮素吸收量对籽粒的贡献率为68.20%和34.84%。（4）相同氮素处理下,扬花至灌浆期大麦茎秆和叶片中营养性氮含量增加,功能性氮含量变化平稳,而结构性氮含量则降低;籽粒营养性氮含量逐渐增加,结构性氮含量缓慢下降。且较低效基因型,高效基因型大麦茎秆和叶片结构性氮含量的降低幅度大,氮素转运能力强。低氮处理下,高效基因型扬花期至灌浆期茎秆和叶片结构性氮含量分别降低49.57%、62.58%;灌浆至成熟期分别降低64.47%、28.11%。【结论】氮高效利用基因型大麦籽粒氮含量受花后茎秆和叶片中结构性氮的分解转化决定,营养器官中结构性氮的再利用有利于氮素利用效率的提高。  相似文献   

14.
A field experiment was conducted to study the impact of tillage, crop residue management and nitrogen (N) splitting on spring wheat (Triticum aestivum L.) yield over 2 yr (2010-2012) in a rice (Oryza sativa L.)-wheat system in northwestern Pakistan. The experiment was conducted as split plot arranged in randomized complete blocks design with three replications. Treatments comprised six tillage and residue managements: zero tillage straw retained (ZTsr), zero tillage straw burnt (ZTsb), reduced tillage straw incorporated (RTsi), reduced tillage straw burnt (RTsb), conventional tillage straw incorporated (CTsi), and conventional tillage straw burnt (CTsb) as main plots and N (200 kg ha−1) was applied as split form viz., control (no nitrogen & no splitting, N0S0); 2 splits of total N, half at sowing and half at the 1st irrigation (i.e., 20 d after sowing (DAS)) (NS1); 3 splits of total N, 1/3 at sowing, 1/3 at the 1st irrigation, and 1/3 at the 2nd irrigation (NS2); 4 splits of total N, 1/4 at sowing, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation (45 DAS), and 1/4 at the 3rd irrigation (70 DAS) (NS3); and 4 splits of total N, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation, 1/4 at the 3rd irrigation, and 1/4 at the 4th irrigation (95DAS) (NS4) as sub plots. The results showed that the most pikes m−2, grains/spike, 1000-grain weight, grain yield, and N use efficiency (NUE) were obtained at zero tillage, straw retained and 4 splits application of total N (i.e., at sowing 20, 45 and 70 d after sowing). The results indicated that ZTsr with application of 200 kg N ha−1 in 4 equal splits viz. at sowing 20, 45 and 70 d after sowing is an appropriate strategy that enhanced wheat yield (7436-7634 kg ha−1) and N efficiency (28.6-29.5 kg kg−1) in rice-wheat system.  相似文献   

15.
In China, the abuse of chemical nitrogen(N) fertilizer results in decreasing N use efficiency(NUE), wasting resources and causing serious environmental problems. Cereal-legume intercropping is widely used to enhance crop yield and improve resource use efficiency, especially in Southwest China. To optimize N utilization and increase grain yield, we conducted a two-year field experiment with single-factor randomized block designs of a maize-soybean intercropping system(IMS). Three N rates, NN(no nitrogen application), LN(lower N application: 270 kg N ha–1), and CN(conventional N application: 330 kg N ha–1), and three topdressing distances of LN(LND), e.g., 15 cm(LND1), 30 cm(LND2) and 45 cm(LND3) from maize rows were evaluated. At the beginning seed stage(R5), the leghemoglobin content and nitrogenase activity of LND3 were 1.86 mg plant–1 and 0.14 m L h–1 plant–1, and those of LND1 and LND2 were increased by 31.4 and 24.5%, 6.4 and 32.9% compared with LND3, respectively. The ureide content and N accumulation of soybean organs in LND1 and LND2 were higher than those of LND3. The N uptake, NUE and N agronomy efficiency(NAE) of IMS under CN were 308.3 kg ha–1, 28.5%, and 5.7 kg grain kg–1 N, respectively; however, those of LN were significantly increased by 12.4, 72.5, and 51.6% compared with CN, respectively. The total yield in LND1 and LND2 was increased by 12.3 and 8.3% compared with CN, respectively. Those results suggested that LN with distances of 15–30 cm from the topdressing strip to the maize row was optimal in maize-soybean intercropping. Lower N input with an optimized fertilization location for IMS increased N fixation and N use efficiency without decreasing grain yield.  相似文献   

16.
Excessive nitrogen(N) fertilization with a high basal N ratio in wheat can result in lower N use efficiency(NUE) and has led to environmental problems in the Yangtze River Basin, China. However, wheat requires less N fertilizer at seedling growth stage, and its basal N fertilizer utilization efficiency is relatively low; therefore, reducing the N application rate at the seedling stage and postponing the N fertilization period may be effective for reducing N application and increasing wheat yield and NUE. A 4-year field experiment was conducted with two cultivars under four N rates(240 kg N ha–1(N240), 180 kg N ha–1(N180), 150 kg N ha–1(N150), and 0 kg N ha–1(N0)) and three basal N application stages(seeding(L0), fourleaf stage(L4), and six-leaf stage(L6)) to investigate the effects of reducing the basal N application rate and postponing the basal N fertilization period on grain yield, NUE, and N balance in a soil-wheat system. There was no significant difference in grain yield between the N180 L4 and N240 L0(control) treatments, and the maximum N recovery efficiency and N agronomy efficiency were observed in the N180 L4 treatment. Grain yield and NUE were the highest in the L4 treatment. The leaf area index, flag leaf photosynthesis rate, flag leaf nitrate reductase and glutamine synthase activities, dry matter accumulation, and N uptake post-jointing under N180 L4 did not differ significantly from those under N240 L0. Reduced N application decreased the inorganic N content in the 0–60-cm soil layer, and the inorganic N content of the L6 treatment was higher than those of the L0 and L4 treatments at the same N level. Surplus N was low under the reduced N rates and delayed basal N application treatments. Therefore, postponing and reducing basal N fertilization could maintain a high yield and improve NUE by improving the photosynthetic production capacity, promoting N uptake and assimilation, and reducing surplus N in soil-wheat systems.  相似文献   

17.
The influence of agricultural management practices, such as organic fertilisation and plant densities on soil properties, root growth, and sesame yield were investigated. Soil samples (depth of 0–20 cm) were taken from a field study with sesame (Sesamum indicum L.) cultivated on a Chromic Luvisol, which was conducted to explore the effects of six fertilisation systems [Non-fertilisation (Control); Mineral fertilisation (Min); Organic fertilisation with 2 (Org-1) and 3 Mg ha–1 (Org-2) of commercial organic fertiliser Organus B; and with 1 (Tak 1) and 2 Mg ha–1 (Tak-2) of commercial organic fertiliser Takamix] and two plant densities [111111 (Pdens1) and 55555 (Pdens2) plants ha–1), in a factorial design (6 × 2) with four blocks. The highest values of soil organic carbon, total nitrogen, root density and sesame yield were found in the Org-2 fertilisation and Pdens1 treatments. We found that organic fertilisation combined with Pdens1 significantly increased root growth. Organic fertilisation treatments were able to maintain 80% of sesame roots distributed at a soil depth of 0–10 cm, whereas the last 20% were distributed at a soil depth of 10.1–20 cm. In conclusion the utilization of commercial organic fertilisers as an organic matter source enhanced soil organic carbon, total nitrogen, and root density that contributed to increase sesame yield. Our findings also suggest that inputs of organic matter source with a correct plant density might change positively soil organic carbon and total nitrogen, root growth, root distribution and sesame yield.  相似文献   

18.
《农业科学学报》2023,22(6):1883-1895
Ammonia (NH3) emissions should be mitigated to improve environmental quality. Croplands are one of the largest NH3 sources, they must be managed properly to reduce their emissions while achieving the target yields. Herein, we report the NH3 emissions, crop yield and changes in soil fertility in a long-term trial with various fertilization regimes, to explore whether NH3 emissions can be significantly reduced using the 4R nutrient stewardship (4Rs), and its interaction with the organic amendments (i.e., manure and straw) in a wheat–maize rotation. Implementing the 4Rs significantly reduced NH3 emissions to 6 kg N ha–1 yr–1 and the emission factor to 1.72%, without compromising grain yield (12.37 Mg ha–1 yr–1) and soil fertility (soil organic carbon of 7.58 g kg–1) compared to the conventional chemical N management. When using the 4R plus manure, NH3 emissions (7 kg N ha–1 yr–1) and the emission factor (1.74%) were as low as 4Rs, and grain yield and soil organic carbon increased to 14.79 Mg ha–1 yr–1 and 10.09 g kg–1, respectively. Partial manure substitution not only significantly reduced NH3 emissions but also increased crop yields and improved soil fertility, compared to conventional chemical N management. Straw return exerted a minor effect on NH3 emissions. These results highlight that 4R plus manure, which couples nitrogen and carbon management can help achieve both high yields and low environmental costs.  相似文献   

19.
应用三因素五水平二次正交旋转组合试验设计方法,研究了“闽甜107”的播种期、种植密度和施氮量对产量及主要性状的影响,建立了相应的数学模型,得出3个因素对产量的作用大小:施氮量>播种期>种植密度,并优选出产量高于817.65kg/667m2的栽培措施:播种期4月1~7日、种植密度3720~3940株/667m2、氮肥施用量16.75~19.75kg/667m2。  相似文献   

20.
《农业科学学报》2023,22(7):2067-2079
Climate change has a significant impact on agriculture. However, the impact investigation is currently limited to the analysis of meteorological data, and there is a dearth of long-term monitoring of crop phenology and soil moisture associated with climate change. In this study, temperature and precipitation (1957–2020) were recorded, crop growth (1981–2019) data were collected, and field experiments were conducted at central and eastern Gansu and southern Ningxia, China. The mean temperature increased by 0.36°C, and precipitation decreased by 11.17 mm per decade. The average evapotranspiration (ET) of winter wheat in 39 years from 1981 to 2019 was 362.1 mm, demonstrating a 22.1-mm decrease every 10 years. However, the ET of spring maize was 405.5 mm over 35 years (1985–2019), which did not show a downward trend. Every 10 years, growth periods were shortened by 5.19 and 6.47 d, sowing dates were delayed by 3.56 and 1.68 d, and maturity dates advanced by 1.76 and 5.51 d, respectively, for wheat and maize. A film fully-mulched ridge–furrow (FMRF) system with a rain-harvesting efficiency of 65.7-92.7% promotes deep rainwater infiltration into the soil. This leads to double the soil moisture in-furrow, increasing the water satisfaction rate by 110-160%. A 15-year grain yield of maize increased by 19.87% with the FMRF compared with that of half-mulched flat planting. Grain yield and water use efficiency of maize increased by 20.6 and 17.4% when the density grew from 4.5×104 to 6.75×104 plants ha–1 and improved by 12.0 and 12.7% when the density increased from 6.75×104 to 9.0×104 plants ha–1, respectively. Moreover, responses of maize yield to density and the corresponding density of the maximum yield varied highly in different rainfall areas. The density parameter suitable for water planting was 174 maize plants ha–1 with 10 mm rainfall. Therefore, management strategies should focus on adjusting crop planting structure, FMRF water harvesting system, and water-suitable planting to mitigate the adverse effects of climate change and enhance sustainable production of maize in the drylands.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号