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1.
《European Journal of Agronomy》1999,10(2):73-79
In order to limit overproduction and pollution risks, low N fertiliser agricultural systems are likely to be advocated in Europe. An experiment was carried out in 1994 and 1995 to compare N uptake and N utilisation of two-rowed and six-rowed winter barley (Hordeum vulgare L.). Two sets of two-rows and six-rows, composed of 18 varieties each, were cultivated in northern France on a haplic luvisol without (N1) and with 100–110 kg/ha (N2) N fertiliser. Mean grain yield was 596 g/m2 at N1 and 779 g/m2 at N2. On average six-rows outyielded two-rows by 4% (34 g/m2) at N2 and 11% at N1 (70 g/m2). Ears/m2 was the yield component which fell most sharply between N2 and N1 (718 and 510 ears/m2 on average). Six-rows had fewer ears/m2 at both N levels but they lost more ears than two-rows (−33% and −26%, respectively). While the number of grains/ear was approximately the same for two-rows at both N levels (21.9 grains/ear on average) in 1995, it was significantly higher at N1 than at N2 for six-rows (44.7 and 38.5, respectively). Thousand kernel weight was higher at N1 than at N2, the difference being higher for six-rows (+7%) than for two-rows (+4%). N uptake efficiency (total plant N/soil N supply) was identical at N2 and higher for six-rows at N1 in 1995. Total N utilisation efficiency (total above-ground dry weight/total plant N) was equal at both N levels. HI (grain yield/total above-ground dry weight) was higher at N1 in both years and at N2 in 1994 for six-rows. Six-rows outyielded two-rows at high and low N levels. This was therefore associated mainly with higher HI and not with better N uptake or utilisation efficiency. 相似文献
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3.
施氮量对垄作小麦氮肥利用率和土壤硝态氮含量的影响 总被引：10，自引：0，他引：10
以平作为对照,研究了垄作种植方式下施氮量对冬小麦氮肥吸收利用、0~100 cm土层土壤硝态氮含量以及产量的影响。在一定范围内增加施氮量,小麦的氮肥利用率降低,土壤氮的贡献率降低,小麦植株内的氮素积累量增加,收获指数提高,产量增加。低氮(0~66 kg hm-2)条件下,小麦生育期间土壤硝态氮淋洗损失的可能小,小麦收获后0~100 cm土体内不会累积大量硝态氮。施氮量在165~264 kg hm-2时,60~100 cm土体内土壤硝态氮含量增加,出现硝态氮下移趋势。种植方式影响小麦的氮肥利用效率,垄作种植小麦氮肥利用率和产量均高于平作小麦。垄作种植麦田60~80 cm土体内土壤硝态氮含量相对较高,而平作种植麦田80~100 cm土层硝态氮含量相对较高。种植方式对氮肥利用率的影响大于施氮量的影响, 但施氮量对氮素收获指数、籽粒产量以及经济系数的影响大于种植方式的影响。本试验条件下,2种种植方式在施氮量为纯氮165 kg hm-2时可以获得较高的氮肥利用率和氮素收获指数,平作小麦氮肥利用率为35.75%~36.41%,而垄作小麦为45.32%~47.25%; 但2种种植方式的小麦都是施氮量为纯氮264 kg hm-2时获得最高产量, 平作和垄作小麦的最高产量分别达8 078.31 kg hm-2和
8 212.27 kg hm-2。 相似文献
4.
A model to describe the importance of different physiological processes to explain grain yield differences (ΔGw) between cropping systems (Huggins and Pan, 1993) was modified to evaluate the nitrogen use efficiency of different cereals. The method uses measurements of grain yield (Gw), grain N (Ng), above-ground plant biomass (B), above-ground plant N (Nt), applied fertilizer N (Nf), and post-harvest inorganic soil N in control plots without fertilizer (Nh). The components are N supply (Ns), N uptake efficiency (Nt/Ns), assimilation efficiency (B/Nt), harvest index (Gw/B) and N harvest index (Ng/Nt). For a first verification of the model different winter cereal species, i.e., one genotype of winter wheat, one of winter rye and one of spelt wheat, were compared in a 2-year field experiments at two sites with different soil fertility and climate. The modified nitrogen efficiency component analysis provided a good understanding of yield differences at different levels of applied N and soil fertility. The method could be useful for selection of genotypes with a high N use efficiency in breeding programmes. 相似文献
5.
An understanding of the partition between pre-anthesis and post-anthesis N uptake and their contribution to total grain N and protein content in spring two-rowed barley (Hordeum vulgare spp. distichum L.) is important to achieve additional breeding progress for both fodder and malting barley. N translocation from the vegetative tissues at anthesis to the kernel, N translocation efficiency, and N harvest index (NHI) were studied in field experiments during 4 years (1995–1998). Plants were harvested at anthesis and maturity and divided into leaf+culm, chaff and grain. Significant cultivar differences in N translocation, N translocation efficiency and NHI were determined. Across cultivars, the highest N translocation was in a favorable year (93 kg ha−1) and the lowest in a year with poor growing conditions (40 kg ha−1). Cultivar differences in N translocation were related to dry matter and pre-anthesis N accumulation (R2>0.70). N translocation efficiency varied more among the cultivars (0.27–0.66) than years (0.47–0.52). Post-anthesis N uptake was negatively correlated (P<0.01) with N translocation. NHI ranged among the cultivars from 0.49 to 0.73 and among the years from 0.57 to 0.74. The cultivars Arapiles, Schooner, Cantala, Kaskade and Pek stored in the grain more than 70% and Hiproly less than 50% of above-ground N at maturity. Translocated N participated with 85, 56, 42, and 61% in grain N in 1995, 1996, 1997, and 1998, respectively. The ratio of translocated N to grain N could be an indicator of growing conditions; a higher ratio indicates good growing conditions over the entire growth period, a lower ratio indicates poor conditions during pre-anthesis, and a medium ratio indicates some temperature and water deviations from the long-term average. Straw N concentration was in significant positive (P<0.01) correlation with N translocation and translocation efficiency. Straw N concentration adequately represents N efficiency utilization for synthesis of grain protein, and because it saves time and money compared to N harvest index determination, it can be used for the testing of breeding materials for the development of new barley cultivars. 相似文献
6.
Relationship between grain yield and grain nitrogen concentration in winter triticale 总被引：1，自引：0，他引：1
Summary Ten hexaploid winter triticale lines were grown for two cropping periods at three locations in western Switzerland. Averaged across the six environments, the differences between lines were statistically significant (P=0.05) for grain yield, above-ground biomass, N uptake, grain N yield, nitrogen harvest index, grain N concentration and straw N concentration. There were significant line x environment interactions for all traits. Grain yield and grain N concentration were inversely related (r=–0.74**). Diagrams in which grain yields were plotted against grain N concentration were used to identify lines with a consistently unusual combination of grain yield and grain N concentration. Despite comparable grain yields, Line 3 had a high grain N concentration, while that of Line 7 was low. Line 3 was superior to Line 7 in both N uptake and N harvest index. Averaged across environments and lines, the N harvest index was 0.73 which corresponds to N harvest indices reported for bread wheat in the same region. We considered the feasibility of developing triticale lines which would outperform the best recent ones in N uptake and partitioning. However, we doubted that this would bring about a marked increase in grain N concentration, because, in the long run, the expected genetic progress in grain yield will lead to a dilution of grain protein by grain carbohydrate increments.Abbreviations GNC
grain N concentration
- GNY
grain N yield
- GY
grain yield
- HI
above-ground dry matter harvest index
- NHI
nitrogen harvest index
- SNC
straw N concentration
- TB
total above-ground biomass
- TPN
total plant N 相似文献
7.
Nitrogen uptake and utilization efficiency of European maize hybrids developed under conditions of low and high nitrogen input 总被引：15，自引：0，他引：15
T. Presterl S. Groh M. Landbeck G. Seitz W. Schmidt H. H. Geiger 《Plant Breeding》2002,121(6):480-486
Maize varieties with improved nitrogen(N)‐use efficiency under low soil N conditions can contribute to sustainable agriculture. Tests were carried to see whether selection of European elite lines at low and high N supply would result in hybrids with differential adaptation to these contrasting N conditions. The objective was to analyze whether genotypic differences in N uptake and N‐utilization efficiency existed in this material and to what extent these factors contributed to adaptation to low N supply. Twenty‐four hybrids developed at low N supply (L × L) were compared with 25 hybrids developed at high N supply (H × H). The N uptake was determined as total above‐ground N in whole plants, and N‐utilization efficiency as the ratio between grain yield and N uptake in yield trials at four locations and at three N levels each. Highly significant variations as a result of hybrids and hybrids × N‐level interaction were observed for grain yield as well as for N uptake and N‐utilization efficiency in both hybrid types. Average yields of the L × L hybrids were higher than those of the H × H hybrids by 11.5% at low N supply and 5.4% at medium N level. There was no significant yield difference between the two hybrid types at high N supply. The L × L hybrids showed significantly higher N uptake at the low (12%) and medium (6%) N levels than the H × H hybrids. In contrast, no differences in N‐utilization efficiency were observed between the hybrid types. These results indicate that adaptation of hybrids from European elite breeding material to conditions with reduced nitrogen input was possible and was mainly the result of an increase in N‐uptake efficiency. 相似文献
8.
施氮量对酿造高粱产量和氮素利用率的影响 总被引：1，自引：0，他引：1
为了实现酿造高粱氮肥合理高效利用,以晋杂22号为试验品种,研究了6种氮肥施用量(0,75,150,225,300,450 kg/hm~2)对酿造高粱产量和氮素利用率的影响。结果表明,在施氮0~450 kg/hm~2,施用氮肥有效地增加了高粱产量和净利润,但随着施氮量的增加产量先升高后降低,其关系可表示为y=-0.037x~2+17.759x+5 874.41(R2=0.878 1)。随着施氮量的增加高粱氮肥偏生产力和氮肥利用率显著降低;氮素吸收效率逐渐降低;氮素利用效率大体呈下降趋势;当施氮量为225 kg/hm~2时,高粱产量、净利润最大,极显著高于不施氮处理,增产率达37.64%;氮肥农学利用率和氮肥偏生产力分别为9.96,36.42 kg/kg,氮肥利用率可达到38.70%,且氮平衡为3.07,大体上满足氮素平衡。综合分析各项指标,施氮量为225 kg/hm~2是酿造高粱晋杂22号实现高产、高效益、较高氮肥利用率的适宜氮量。 相似文献
9.
Dense planting and less basal nitrogen (N) fertilization have been recommended to further increase rice (Oryza sativa L.) grain yield and N use efficiency (NUE), respectively. The objective of this study was to evaluate the integrative impacts of dense planting with reduced basal N application (DR) on rice yield, NUE and greenhouse gas (GHG) emissions. Field experiments with one conventional sparse planting (CK) and four treatments of dense planting (increased seedlings per hill) with less basal N application were conducted in northeast China from 2012 to 2013. In addition, a two-factor experiment was conducted to isolate the effect of planting density and basal N rate on CH4 emission in 2013. Our results show that an increase in planting density by about 50% with a correspondingly reduction in basal N rate by about 30% (DR1 and DR2) enhanced NUE by 14.3–50.6% and rice grain yield by 0.5–7.4% over CK. Meanwhile, DR1 and DR2 reduced GWP by 6.4–12.6% and yield-scaled GWP by 7.0–17.0% over CK. According to the two-factor experiment, soil CH4 production and oxidation and CH4 emission were not affected by planting density. However, reduced basal N rate decreased CH4 emission due to it significantly reduced soil CH4 production with a smaller reduction in soil CH4 oxidation. The above results indicate that moderate dense planting with less basal N application might be an environment friendly mode for rice cropping for high yield and NUE with less GHG emissions. 相似文献
10.
The Montepaldi Long Term Experiment (MOLTE) trial in central Italy has been comparing three agroecosystems with different management: two organic (Old Organic since 1992 and Young Organic since 2001) and one conventional. After sixteen years of comparison, the agronomic performance and environmental sustainability of the three agro-ecosystems were assessed. Crops grain yield, total C inputs and N budget at field level were evaluated. N use efficiency (NUE) at micro-agroecosystem level was determined. Soil samples were collected from the three agroecosystems in order to quantify soil C and N pools.Results showed comparable grain yields in the three agro-ecosystems. The conventional system showed a larger N surplus and a lower crop N use efficiency in comparison with the organic ones. Moreover, the organic systems presented a lower potential risk of N losses with respect to the conventional one. The Young Organic agro-ecosystem was the most effective in terms of long term soil C (13% higher than conventional) and the oldest organic agro-ecosystem was the most effective in terms of soil N storage (9% higher than conventional).The results obtained demonstrated that the application of the organic farming method could increase the environmental sustainability in stockless arable systems under Mediterranean type of climate. 相似文献
11.
From all plant nutrients N fertilizer rates deserve highest attention as too high rates may result in nitrate leaching, volatilisation of N2O (greenhouse gas) and affect the farmers’ profit. Too low rates will also depress the profit. The problem is accentuated by the fact that crops not only feed from soil inorganic but also from organic soil N. Most soil N tests do not consider the available organic soil N. The Electro-Ultra-Filtration (EUF) method applied by us takes into account the EUF extractable inorganic and organic soil N for calculating the N fertilizer rate. This method developed at the Liebig University Giessen is called Giessen model (sampling in autumn out of the upper soil layer, 0–30 cm). We compared it with the standard soil N test the “Nmin method” recommended by German officials which method does not consider the available organic soil N (sampling in spring out of three or two soil layers, depending on soil depth). The investigation was carried out on farmers’ fields on five different sites with winter cereals (wheat, barley) in 1989/1990, 1990/1991 and 1991/1992. Recommended fertilizer application rates differed somewhat for both methods. Of the 23 cases, significantly higher grain yields were obtained five times by Nmin and four times by EUF; otherwise grain yields did not differ significantly between both methods. Grain yield and crude protein concentration were increased by fertilizer N compared with the plots without N fertilizer. On the site Giessen, however, there were some cases in which the N fertilizer did not increase grain yield. The soil of the Giessen site was rich in interlayer NH4+ which is not recovered by the EUF and Nmin method, but which obviously contributed to the N supply of the crop, and therefore the N rates were too high. Grain crude protein concentration were higher with Nmin for Wernborn and Bruchkobel sites because of higher N fertilizer rates. For the Giessen site in 1989/1990 the reverse was true. Nitrogen agronomic efficiency (AE) ranged from 0 to 35.6. Apparent N recovery (ANR) ranged from 0 to 111. The gross profit differed from −88 to 489 Euro/ha. Negative values (three cases out of 23) were found on the Giessen site where no yield increase was obtained by the N fertilizer because of interlayer NH4+. This interpretation is supported by the finding that interlayer NH4+ significantly decreased from autumn to spring. Apart from the results found in 1 year on the Giessen site, the gross profit calculation showed that a precise N fertilizer application based on soil analysis yields a high profitability of cereal production. 相似文献
12.
以水稻品种南粳9108为试验对象,于2019-2020年在扬州大学校内试验基地采用盆栽试验研究纳米镁（12kg Mg/hm2）在0、225、270、315kg N/hm2条件下对水稻的产量、稻米品质及氮素利用率的影响。结果表明,纳米镁的施用能有效提高产量和氮肥利用率。相同氮肥施用水平下,施用纳米镁处理的水稻产量均高于不施镁处理,2年籽粒产量分别提高2.85%~8.86%和5.22%~7.16%,单位面积穗数和穗粒数显著提高。与不施镁处理相比,施用纳米镁处理的氮肥利用率提高了4.18%~5.97%,稻米品质也有一定改善。施用纳米镁处理的稻米整精米率和蛋白质含量分别提高了3.51%和6.26%,垩白粒率、垩白度和直链淀粉含量分别降低了2.45%、2.40%和4.30%,胶稠度变化不明显。与不施镁处理相比,施用纳米镁处理的稻米食味值、峰值黏度、热浆黏度和崩解值分别提高了0.79%、1.35%、1.64%和0.48%,最终黏度降低了0.66%,但均未达到显著差异。兼顾产量和稻米品质,在225~270kg/hm2的施氮量下,施用纳米镁有利于实现水稻的高产高效优质栽培。 相似文献
13.
Importance of P uptake efficiency versus P utilization for wheat yield in acid and calcareous soils in Mexico 总被引：1，自引：0，他引：1
G. G. B. Manske J. I. Ortiz-Monasterio M. van Ginkel R. M. Gonzlez R. A. Fischer S. Rajaram P. L. G. Vlek 《European Journal of Agronomy》2001,14(4):261-274
There are large agricultural areas in the world where wheat yields are limited by low phosphorus (P) availability. Breeding for P uptake and P utilization efficiency may reduce this problem. This study was conducted to determine the contribution of P uptake and utilization efficiency to grain yield of selected spring wheat genotypes in different environments. Thirty-eight semidwarf spring bread wheat (Triticum aestivum) genotypes were grown in two experiments in Mexico, each on an acid Andisol under rainfed conditions and on a calcareous Aridisol with irrigation, without (−P) and with 35 kg P per ha fertilized (+P). Without P fertilization, grain yield ranged from 0.8 to 4.6 t ha−1 in the acid soil and from 2.4 to 5.2 t ha−1 in the calcareous soil. With P fertilization, this range was even larger. Under conditions of P deficiency, i.e. in the acid soil at −P and +P (high P adsorption) and calcareous soil at −P (P-depleted soil), P uptake explained 71–100% of the variation in grain yield, and was highly correlated with grain yield (r=0.79–0.95). In contrast, at +P in the calcareous soil, P utilization efficiency explained 60–63% of the variation in grain yield. Here, low grain P concentration was related to high grain yield (r=−0.40 to −0.59). In the calcareous soil, the harvest index was correlated with grain yield, irrespective of the P level. In the acid soil, post-anthesis P accumulation was important. It was positively correlated with grain yield, whereas in the calcareous soil, no post-anthesis-P accumulation occurred. Here, grain P accumulation at maturity was completely determined by translocation of pre-anthesis shoot P. We conclude that the combination of improved P uptake and P utilization efficiency in the same genotypes requires selection under both high and low-P conditions. 相似文献
14.
Plant breeding is a powerful tool for improving nitrogen (N) uptake efficiency and thus reducing the environmental impact relating to crop production. This study evaluated the environmental impact of current barley production systems in two Swedish agricultural areas (South and East) compared with scenarios with improved N uptake efficiency at two levels, in which the fraction of mineral N available for daily crop uptake was increased by 50 and 100%. Life cycle assessment (LCA) methodology was used to quantify energy use, global warming potential (GWP) and acidification and eutrophication potentials along the production chain for spring barley with differing N uptake efficiency, but similar N application rate. The functional unit, to which all energy use and emissions were related, was 1 Mg barley grain. Energy use, GWP and acidification proved to be higher for the East production system, mainly due to lower yield, while eutrophication was higher for South. The two impacts most affected by improved N uptake efficiency were eutrophication and GWP, with GWP decreasing due to a combination of higher yield, soil carbon sequestration and lower indirect emissions of N2O due to lower N leaching. Accounting for land savings due to increased yield, reducing the pressure to transform land elsewhere, would further lower the carbon footprint. Potential eutrophication per Mg grain was reduced by 15% in the production system with the highest N uptake efficiency in southern Sweden. Crops with improved N uptake efficiency can thus be an important complementary measure for reducing N losses to water, provided that the N application rate does not increase. However, incentives for farmers to maintain or even lower the N application rate might be required. Using simulation modelling is a promising approach for assessment of expected effects of improved crop varieties when no long-term experimental data are available. However, advanced crop models are required to better reflect the effect of plant breeding on e.g. expected yield. Future model development should involve expertise in plant breeding, plant physiology and dynamic crop and soil modelling. 相似文献
15.
高产条件下施氮量对冬小麦氮素吸收分配利用的影响 总被引：59，自引：8，他引：59
通过2年田间定位试验,采用15N示踪技术,研究了高产条件下不同施氮量处理对冬小麦氮素吸收、分配、利用及产量和品质的影响。结果表明,在本试验土壤肥力条件下,当施氮量超过150 kg/hm2时,不能显著增加植株氮素积累量,对小麦生育后期植株氮素吸收无显著促进效应。随施氮量增加,氮素在籽粒中的分配比例降低,在茎和叶的分配量及比例显著增加。15N示踪试验指出,施氮量由195 kg/hm2增至240 kg/hm2,植株吸收的肥料氮素增加,吸收的土壤氮素减少,植株总的氮素积累量无显著差异;施氮量增加,开花后营养器官中的氮素向籽粒的转移无显著差异,而转移效率及氮素转移对籽粒的贡献率降低。施氮量增加,氮素吸收效率和氮素利用效率下降,氮肥生产效率降低,氮素收获指数亦降低。施氮量为105～240 kg/hm2时,氮肥当季回收率为36.22%～50.54%,其中追肥氮回收率大于基肥氮;施氮量增加,氮肥回收率先增加后降低,195 kg/hm2处理氮肥当季回收率较高。适量施氮,籽粒产量增加,蛋白质含量提高,加工品质改善;过量施氮,籽粒产量降低,加工品质趋于变劣。本试验条件下,综合考虑产量、品质和氮素利用率,施氮量为150～195 kg/hm2可供生产中参考。 相似文献
16.
Nitrogen recommendation systems for sugarcane (Saccharum spp.) generally does not consider the N supply from soil. Identifying a reliable soil test for estimating N availability is crucial to avoid yield losses or environmental pollution. Therefore, the objective of this study was to correlate and calibrate N availability indices with field–based measures of soil N supply. Between 2006 and 2013, 15 trials for rate–response to N fertilizer by sugarcane ratoons were performed in São Paulo, the main sugarcane–producing state in Brazil. The following indices were tested: KMnO4 oxidizable C, hot KCl extractable N, phosphate–borate buffer distillable N, NaOH distillable N, Illinois Soil N Test, organic C, total N, mineral N, anaerobic incubation, soil respiration, substrate–induced respiration, microbial biomass C, metabolic quotient, microbial quotient, and gross N mineralization. The indices were then correlated with sugarcane yield (Y0N) and N content of the crop (N0N) in N–unfertilized plots, relative yield (RY), and the N rate predicted to achieve 90% of the RY (NR 90%RY). Although weak correlations were found between Y0N with anaerobic incubation, total N, and soil respiration, as well as between N0N and anaerobic incubation, no index correlated with RY or NR 90%RY. Grouping sites based on soil texture or byproduct management did not improve prediction of RY. Therefore, we concluded that none of the fifteen laboratory indices is a reliable predictor of soil N supply, and hence could not be used to adjust N fertilization rate for sugarcane. 相似文献
17.
Upendra M. Sainju Wayne F. Whitehead Bharat P. Singh Shirley Wang 《European Journal of Agronomy》2006,25(4):372-382
Sustainable soil and crop management practices that reduce soil erosion and nitrogen (N) leaching, conserve soil organic matter, and optimize cotton and sorghum yields still remain a challenge. We examined the influence of three tillage practices (no-till, strip till and chisel till), four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secaele cereale L.)], vetch/rye biculture and winter weeds or no cover crop}, and three N fertilization rates (0, 60–65 and 120–130 kg N ha−1) on soil inorganic N content at the 0–30 cm depth and yields and N uptake of cotton (Gossypium hirsutum L.) and sorghum [Sorghum bicolor (L.) Moench]. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) from 1999 to 2002 in Georgia, USA. Nitrogen supplied by cover crops was greater with vetch and vetch/rye biculture than with rye and weeds. Soil inorganic N at the 0–10 and 10–30 cm depths increased with increasing N rate and were greater with vetch than with rye and weeds in April 2000 and 2002. Inorganic N at 0–10 cm was also greater with vetch than with rye in no-till, greater with vetch/rye than with rye and weeds in strip till, and greater with vetch than with rye and weeds in chisel till. In 2000, cotton lint yield and N uptake were greater in no-till with rye or 60 kg N ha−1 than in other treatments, but biomass (stems + leaves) yield and N uptake were greater with vetch and vetch/rye than with rye or weeds, and greater with 60 and 120 than with 0 kg N ha−1. In 2001, sorghum grain yield, biomass yield, and N uptake were greater in strip till and chisel till than in no-till, and greater in vetch and vetch/rye with or without N than in rye and weeds with 0 or 65 kg N ha−1. In 2002, cotton lint yield and N uptake were greater in chisel till, rye and weeds with 0 or 60 kg N ha−1 than in other treatments, but biomass N uptake was greater in vetch/rye with 60 kg N ha−1 than in rye and weeds with 0 or 60 kg N ha−1. Increased N supplied by hairy vetch or 120–130 kg N ha−1 increased soil N availability, sorghum grain yield, cotton and sorghum biomass yields, and N uptake but decreased cotton lint yield and lint N uptake compared with rye, weeds or 0 kg N ha−1. Cotton and sorghum yields and N uptake can be optimized and potentials for soil erosion and N leaching can be reduced by using conservation tillage, such as no-till or strip till, with vetch/rye biculture cover crop and 60–65 kg N ha−1. The results can be applied in regions where cover crops can be grown in the winter to reduce soil erosion and N leaching and where tillage intensity and N fertilization rates can be minimized to reduce the costs of energy requirement for tillage and N fertilization while optimizing crop production. 相似文献
18.
施氮量对小麦花后氮素分配及氮素利用的影响 总被引：3，自引：0，他引：3
为研究黄淮海麦区化肥投入不断增加,而产量却徘徊不前的问题,以当地主栽品种矮抗58和周麦22为材料,采用4个施氮水平（0、120、240、360kg/hm 2）和品种的二因素分析方法研究了施氮量对小麦植株地上部各器官氮素分配及氮素利用的影响。结果表明：开花期至成熟期小麦植株地上部各营养器官氮含量和氮素积累量均下降。施氮量对开花期和成熟期小麦植株地上部各器官氮含量的影响均达显著水平,增加氮肥能显著促进小麦营养器官氮素向子粒转运和花后氮同化。开花期周麦22叶片氮素转运量优于矮抗58。矮抗58和周麦22花后氮同化量均以施氮量360kg/hm 2最高,花前氮素积累转运量对子粒贡献率达60.25%~97.55%,子粒氮收获指数为59.82%~79.48%,随施氮量的增加而呈下降趋势。施氮量120kg/hm 2处理的氮素养分利用效率、农学利用效率及生产效率均最高。增施氮肥对小麦子粒产量有显著促进影响,矮抗58在施氮量为360kg/hm 2时有最大子粒产量,周麦22在施氮量为240kg/hm 2时有最大子粒产量。推荐矮抗58和周麦22在黄淮海麦区的施氮量为240~360kg/hm 2。 相似文献
19.
乙烯利和氮肥对夏玉米氮素吸收与利用及产量的调控效应 总被引：3，自引：0，他引：3
以玉米品种"郑单958"为材料,在大田条件下,研究了乙烯利(0和180 g hm–2)和氮肥水平(0、75、150和225kg N hm–2)对夏玉米产量、氮素吸收和利用以及SPAD值的影响。结果表明,乙烯利处理显著降低了氮吸收量和吸收效率,但显著提高氮利用效率,其中乙烯利处理氮农学效率比对照提高了32.7%~34.6%,而且乙烯利处理对玉米产量及其产量构成因素没有显著影响;随着施氮量增加,夏玉米产量、产量构成因素和氮吸收量显著增加,而氮吸收效率、氮利用效率、氮偏生产力和氮农学效率随之降低,其中225 kg N hm–2处理氮吸收量比0 kg N hm–2处理提高了68.4%~91.8%,但225 kg N hm–2和150 kg N hm–2处理之间的氮吸收量差异不显著。乙烯利和氮肥对氮吸收量、氮吸收效率和氮农学效率具有互作效应。喷施乙烯利和增施氮肥均能提高灌浆期穗位叶SPAD值,但两者之间没有互作效应。通过相关性分析表明,夏玉米产量与吐丝期氮吸收量、收获期氮吸收量、灌浆期穗位叶SPAD值显著正相关。 相似文献
20.
长期施用不同剂量氮肥对高粱产量、氮素利用特性和土壤硝态氮含量的影响 总被引：1，自引：0，他引：1
To determine a suitable nitrogen fertilizer application rate, an experiment was conducted using Jinza 34, Liaoza 27, Jinsi 2, Jinnuo 3, and Fenjiuliang 1 with six nitrogen (N) fertilization levels, including 0 (N0), 75 (N75), 150 (N150), 225 (N225), 300 (N300), and 450 kg hm-2 (N450). The effects of long-term nitrogen fertilization with different levels on sorghum grain yield, nitrogen use characteristics and soil nitrate nitrogen distribution were investigated. The grain yield, grain number and N accumulation of sorghum increased initially and then tended to be stabile with the increase of nitrogen fertilizer application. Among them, the maximum increase of sorghum under N75 treatment compared with that under N0 treatment was 23.68%, 48.05%, and 51.86%, respectively. With the increase of nitrogen fertilizer application, the grain starch content decreased, while the grain starch yield increased firstly and then decreased. Nitrogen apparent recovery rate, nitrogen fertilizer agronomic efficiency and nitrogen use efficiency which were accumulated for five years were reduced significantly with the increase of nitrogen fertilizer application. Compared with the N150 treatment, nitrogen use efficiency accumulated for five years under N75 treatment, which was 63.01%, was increased by 76.91%. When nitrogen fertilizer application was beyond 225 kg hm-2, after four to five years later, nitrate nitrogen residue was increased rapidly in the 60-200 cm soil layer year by year, NO3--N accumulation peaks distributed in the 0-200 cm soil layer and the risk of nitrate nitrogen leaching was increased. In view of the yield, starch yield, nitrogen utilization and environmental benefit, the reasonable nitrogen fertilizer application for sorghum was between 75 kg hm-2 and 150 kg hm-2. 相似文献