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1.
砾石覆盖厚度对斥水土壤入渗特性的影响及模型优选 总被引:1,自引:1,他引:1
基于室内一维垂直入渗土柱试验,研究砾石覆盖厚度(0,3,6,9,12 cm)对斥水土壤积水入渗及水分再分布的影响,并利用不同入渗模型进行拟合。结果表明:砾石覆盖显著增加斥水土壤湿润锋运移距离(p<0.05);同一时段内,各处理累积入渗量皆高于对照组(p<0.05),斥水性红壤累积入渗量与砾石覆盖厚度呈正相关关系;斥水性红壤初渗率与稳渗率随砾石覆盖厚度变化均可用指数函数来描述,决定系数分别为0.91和0.87,砾石覆盖使得斥水性潮土初渗率与稳渗率增大,其中稳渗率与砾石覆盖厚度呈二次函数关系,决定系数为0.78,覆盖6 cm时稳渗率达到最大;砾石覆盖明显提高斥水土壤剖面平均含水率,斥水性红壤和潮土最大分别增长180.8%和57.6%;隔绝蒸发条件下,再分布过程斥水土壤湿润体含水率表现为停渗时刻>再分布1天>再分布3天>再分布7天;Horton模型对砾石覆盖斥水土壤入渗过程的拟合效果最好,是分析和预测砾石覆盖斥水土壤水分入渗特征的适宜模型。 相似文献
2.
《Communications in Soil Science and Plant Analysis》2012,43(19):2446-2455
ABSTRACTDigestate is increasingly utilized as a fertilizer, and earlier research was dedicated to plant growth and soil properties, with simple little information available regarding the effects of digestate on soil, plant, and microbial communities under saline irrigation. For this reason, a pot experiment with Chinese melon was conducted in a greenhouse, and digestate (1100 L ha?1) and a full recommended dose of NPK fertilizer were used. The melons were irrigated with normal water 0.25 (SL0) and 2 dS/m (SL1) using sodium chloride (NaCl). Application of digestate increased the melon plant height and leaves number significantly (p < 0.05) compared to control and treatments that received full NPK dose, under both water treatments (SL0 and SL1). The maximum plant height (SL0: 161 cm and SL1: 85.5 cm) and leaves number (SL0: 156.33 and SL1: 69.67) were observed when digestate used with NPK fertilizer. Plant fruit length, fruit diameter, sugar content, and yield increased significantly by digestate addition. The melon fruit sugar content values were 12% (SL0) and 9.83% (SL1). Soil electrical conductivity values increased when digestate combined with NPK fertilizer (1.4 dS m?1) particularly, under saline water, while the soil pH is not affected by digestate treatments. Digestate increased bacteria and decreased the number of fungi in the soil. Our results indicated that the usage of digestate could be more effective than NPK fertilizer on plant growth and soil properties. And there is a need to confirm these results in soils more realistic for agricultural field conditions and pay attention to use of digestate with saline irrigation water. 相似文献
3.
不同株距和缓释氮肥配施量下机插杂交稻的产量及光合特性 总被引:6,自引:0,他引:6
【目的】温江地区高产水稻的推荐施氮量为180 kg/hm2,以此为基础,机插稻缓释氮肥与常规尿素适宜配比为7:3基础上,进一步研究密度和缓释氮肥配施量对机插稻分蘖特性、干物质积累量、光合物质生产特性、群体生长率及产量的影响。【方法】采用二因素裂区设计进行了机插杂交稻田间试验。在行距为30 cm下,设3种株距处理为16 cm、18 cm、20 cm;在尿素氮施用量54 kg/hm2下,设4个缓释氮用量为36、66、96和126 kg/hm2,总施氮量相应为90、120、150和180 kg/hm2。在插秧时缓释肥与尿素混合,一次性追施。调查了主要生育期水稻生长和氮素吸收运移量。【结果】缓释氮肥配施量和株距对主要生育期的水稻干物质积累量、光合特性及产量均存在显著或极显著的调控效应,且互作效应显著;缓释氮肥配施量的效应明显高于株距。在机插行距30 cm下,株距为18 cm,总施氮量为150和180 kg/hm2时,可有效提高叶面积指数(LAI)、单茎茎鞘与叶片干物重,叶面积衰减慢,拔节至齐穗期光合势大,群体生长率高,光合特性强,促进干物质累积,在足够穗数的基础上,显著增加了穗粒数,提高了群体颖花量,保持了稳定的结实率和千粒重,从而显著提高机插稻产量。株距为16 cm,施氮量为150 kg/hm2时,水稻群体茎蘖数增长快,拔节后群体茎蘖数缓慢消减,有效穗数足,虽穗粒数显著降低,但有较高的结实率和千粒重,从而协调出较高的产量。而株距为20 cm,配施总氮量为180 kg/hm2处理,在保证有效穗数的基础上,促壮秆和攻大穗,增加了穗粒数,干物质积累量多,灌浆充实量大,千粒重增加。相关性分析表明,株距与缓释氮肥配施量耦合下,尤其以拔节至齐穗期光合势、齐穗期高效LAI与产量相关性较高(r=0.87**~0.91**),对促进增产更为重要。【结论】在机插行距30 cm下,株距为18 cm,缓释氮肥(96 kg/hm2)与常规尿素(54 kg/hm2)配施总氮量为150 kg/hm2时,能充分发挥本区域机插杂交籼稻高产的优势、提高光合物质生产,产量最高可达11463.8 kg/hm2,为本试验的最佳肥密运筹处理。 相似文献
4.
保护性措施对农田土壤风蚀影响的室内风洞模拟 总被引:3,自引:0,他引:3
为寻求合理的保护性耕作措施,试验设计了砾石覆盖、秸秆覆盖、覆盖与留茬组合的措施和4个风速等变量,研究风速、覆盖物和覆盖度与风蚀量、抗风蚀效率、风沙流结构的关系,比较多种措施之间的抗风蚀效果优劣.结果表明:1)4个设定风速下30% ~ 90%覆盖度的秸秆覆盖的抗风蚀效率在54% ~ 92%之间,砾石覆盖为26%~72%,30%的砾石覆盖或30%的秸秆覆盖与3种留茬高度的组合措施下,平均抗风蚀效率均在70% ~ 78%之间;2)随着覆盖度的增加,砾石覆盖措施最小可抑制的有效风速值从8.0 m/s逐渐增大到12.5 m/s,秸秆覆盖措施从10.1m/s增加到了14.3 m/s;3)覆盖处理下0~62 cm高度内的输沙量大部分集中在0~26 cm;4)覆盖与留茬组合措施的输沙量多集中在60 cm以内. 相似文献
5.
Five raised-bed test plots were used to study the effects of cover materials on the leaching of constituents from dolomitic Pb mine tailings over a 2-yr period. The cover materials studied were a fertilizer and seed mixture, anaerobically digested sewage sludge, loam and sod, and fallen leaves from silver maples (Acer Saccharinum); one plot was not covered. Fresh leachates and receiving pool waters were analyzed for ten metals, Si, P, inorganic anions, filterable organic carbon (FOC), and alkalinity. The mixture of fertilizer and seed decreased leaching of Pb and Zn during the first year. The leaf cover increased leaching of Pb during both years; this effect decreased as the leaves weathered. Sludge caused some increase in Pb leaching during the first year, and increased Cd leaching during both years. Concentrations of most leachate constituents decreased, and pH increased in the receiving pools. Concentrations of Pb remained higher in the receiving pool for the leaf-covered plot than in the other pools. Increases in leaching of Pb and Cd with a sludge cover were moderate, and the ability of the material to support plant growth on the tailings suggested that it may be a good medium for inducing growth of vegetative cover on the dolomitic tailings. Other organic materials may cause pronounced increase in the concentration of toxic trace metals in leachate from the tailings. 相似文献
6.
It is widely believed that starter fertilizer applications and fungicide treatments, either separate or in combination, can lead to increased plant stands and yields in cool, wet growing seasons. Over a three year period, tests were conducted to evaluate the efficacy of these treatments on cotton (Gossypium hirsutum L.). Two methods of starter application and two fungicide treatments were evaluated over two planting dates. Seedling stand counts and lint yield were measured. Our results show that on a North Carolina coastal plain soil there were no interactions between the treatments. A placement of starter fertilizer 5 cm to the side and 5 cm below the seed showed to have more consistent results in increasing plant stand and yield over a banded application. Fungicide treatments were not effective in increasing plant stands and increased yield in only one year over the untreated check. Yield was positively influenced by earlier planting dates and stand was found to increase in one year with an earlier planting date. Our results suggest that starter fertilizer applications can increase yield and plant stand in good years, but there is no interaction between starter fertilizers, fungicide treatments, and planting date on well‐drained coastal plain soils. 相似文献
7.
The effects of 20 months of intensive disturbance by humans, as well as the presence of feral hogs Sus scrofa, was measured on vegetation. Both forms of disturbance have been thought severely to affect Hawaiian rain forests by reduction of plant cover and allowing the proliferation of exotic plants. Despite much human use throughout the study area, the only significant (P ≤ 0·05) effects were within 2 m of a trail. This disturbance was limited to vegetation < 10 cm in height. No change in canopy cover or in incidence of exotic plants was noted. Feral hog usage was approximately three times higher in the study area than outside, and caused a great deal of damage to the vegetation. The direct impact of humans is relatively minor, being restricted to < 5% of the area. The greater frequency of hogs in the study area could have an undetermined but possibly serious effect on the vegetation. 相似文献
8.
水肥耦合对番茄光合、产量及水分利用效率的影响 总被引:32,自引:12,他引:20
为研究大棚膜下滴灌灌溉上限与施肥量耦合对番茄光合、产量及水分利用效率的影响,以金鹏1号番茄为试材,按照二元二次正交旋转组合设计原理,建立了光合与产量指标的数学模型,分析了水肥两因子的耦合效应。试验结果表明,所建模型达到显著水平;水对光合的影响大于肥,对产量的影响小于肥,水肥对光合和产量的耦合分别存在显著的负效应和正效应;光合速率随灌溉上限的上升表现出明显的上升趋势,超过一定范围后开始下降;不论灌溉上限高低,光合速率均随施肥量的增加表现出先降低后升高的趋势,变化趋势缓慢;番茄的产量随灌溉上限和施肥定额的增加而显著增加,超过一定范围后产量逐渐降低。得出合理的灌溉施肥指标:灌溉下限为田间持水量的50%,灌溉上限为田间持水量的80%~82%,施肥N 313.75~439.75 kg/hm2、P2O5156.55~219.19 kg/hm2、K2O 313.75~439.75 kg/hm2。此时,番茄的产量达到124 t/hm2、水分利用效率达到43.2 kg/m3。 相似文献
9.
Bermudagrass (Cynodon dactylon), seashore paspalum (Paspalum vaginatum), and weeping lovegrass (Eragrostis curvula) were evaluated for use as a vegetative cover over a brine solid waste surface impoundment. Grass seed and sod were established at soil cap depths of 0, 5.1, 10.2, and 15.3 cm over a brine field. Results indicated that each grass species had benefits for either soil stabilization, phytoremediation, and/or establishing a suitable vegetative cap. Results indicated that seashore paspalum leaf tissue assimilated significantly greater quantities of essential elements potassium (K), magnesium (Mg), sulfur (S), and molybdenum (Mo) compared to bermudagrass, and weeping lovegrass. Seashore paspalum also contained the highest concentration of chloride in the plant tissue, indicating that seashore paspalum could be a potential brine remediator. Seashore paspalum and bermudagrass were suitable vegetative grass species selections for the Gulf Coast states. Bermudagrass and seashore paspalum successfully germinated from seed and established from seed and sod. Weeping lovegrass leaf uptake of Ba and Hg was highest. Therefore, each grass species had benefits being used in a stabilization or remediation environment. 相似文献
10.
Application of starter fertilizer at‐planting is a convenient method of applying phosphorus (P) and pre‐plant nitrogen (N) to cotton (Gossypium hirsutum L.). In addition, the placement of starter fertilizer in‐furrow requires no extra tanks or pumps, and can be tank mixed with at‐planting insecticides, fungicides, or plant growth regulators. Over a four‐year period, tests were initiated to determine the effect of 10–34–0 starter fertilizer applied in‐furrow and in a 5 cm to the side and 5 cm below the seed placement (5 cm x 5 cm). Lint yields were measured all four years. Stand counts, Chambers’ skip index, and plant heights were measured the final year. Placement of starter fertilizer in‐furrow was shown to decrease yields compared to a 5 cm x 5 cm placement and a check two out of four years. Plant stands, skip indexes and plant heights were adversely affected by an in‐furrow placement as well. A 5 cm x 5 cm placement did not significantly differ in terms of yield in any year from the check. Plant stands and skip indexes were not affected, but plant height was increased over the check with one rate of starter placed 5 cm x 5 cm. Our results suggest that in‐furrow placement of starter fertilizer has the potential to negatively affect seedling growth and decrease yields. A 5 cm x 5 cm placement of starter fertilizer, while it may not increase yields, does not incur these risks and is a safe, convenient and inexpensive method of applying P or pre‐plant N. 相似文献
11.
12.
塑料簿膜覆盖下棉花氮素营养特性及增产效果 总被引:1,自引:0,他引:1
本试验应用~(15)N标记硫铵研究塑料薄膜覆盖下直播棉花的氮素营养特性及其增产效果。试验表明:盖膜棉花吸收的总氮量明显高于不盖膜处理,苗期尤为突出,盖膜棉株的总氮量为不盖膜处理的244—267%。盖膜并施肥不仅增加了棉株对土壤氮和肥料氮的吸收利用,而且,通过营养器官输往生殖器官的肥料氮量与土壤氮量也分别比不盖膜处理高50.5%和157%,初花期追肥,于初花—盛花阶段形成了吸收肥料氮的高峰,在棉株吸自肥料的氮素中有63.3—76.6%是在这一阶段吸收的。盖膜棉花对氮肥的当季利用率为36%,比不盖膜处理高9%。盖膜施肥处理棉花的产量最高,每公顷产籽棉2472公斤。 相似文献
13.
高肥力土壤冬小麦生长季肥料氮的去向研究 Ⅰ.冬小麦生长季肥料氮的去向 总被引:22,自引:0,他引:22
用15N示踪微区试验研究了常规灌溉和磷钾供应充足的条件下 ,冬小麦生育期肥料氮的去向。结果表明 ,冬小麦对肥料氮的吸收随施氮量的增加而显著增加 ,收获期冬小麦吸收肥料氮占总吸氮量的比例 45% ,吸收土壤氮占 55%。氮肥在整个作物 土壤体系中的回收率随施氮量的增加而显著减少 ,损失量增加。施氮量为 1 2 0kgN hm2 时 ,氮肥的损失率只有 9% ,在作物中的回收率为 45% ,在 0~ 1 0 0cm土壤中的残留率为 45% ;施氮量为 3 60kgN hm2 时 ,氮肥的损失率为 55% ,在作物中的回收率为2 3 % ,在 0~ 1 0 0cm土壤中的回收率为 2 1 %。残留肥料氮以NH4 N存在的数量很少 ,以NO3 N存在的数量随施氮量的增加而显著升高 ,低量施氮时以有机结合态存在的数量远远高于前两种形态 ,但在高量施氮条件下 ,以有机结合态存在的比例与NO3 N相当。肥料氮在 0~ 1 0 0cm土壤各层次中均有残留 ,随着深度的增加 ,残留量减少。从整体上看 ,肥料氮在收获时往下移动超出 1 0 0cm土体。 相似文献
14.
Acid subsoils and tillage pans limit crop yields on sandy soils of the Southern Coastal Plain of the United States. Studies were conducted for 3 years on two soils with acid subsoils and tillage pans to determine the effect of starter fertilizer (22 kg N, 10 kg P ha−1 and fluid lime (1350 kg ha−1) placement with in-row tillage methods on growth and yield of grain sorghum (Sorghum bicolor (L.) Moench) grown in a conservation-tillage system. Fertilizer and lime were applied in factorial combinations in the in-row subsoil channel, in a narrow (4-mm) slit 18 cm below the tillage pan (slit-tillage), or 7 cm to the side of the row incorporated 7 cm deep. Slit-tillage was as effective as subsoiling in two of the four tests where plant growth and grain yield responded to deep tillage. Of the other two tests where there was a response to deep tillage, slit-tillage resulted in a 6% decrease in grain yield compared to subsoiling in one test, and an 8% yield increase in the other. Starter fertilizer placement was not critical, but response to starter fertilizer occurred only when deep tillage, either in-row subsoiling or slit-tillage, was used in conjunction with the fertilizer. Starter fertilizer consistently increased early-season plant growth; however, yield response to starter fertilizer was highly dependent on rainfall. Starter fertilizer application increased yield in only one of five tests. There was no benefit from injecting lime. 相似文献
15.
启动磷肥不同施用方式对玉米养分吸收及生长和产量的影响 总被引:1,自引:0,他引:1
为了探索启动磷肥不同施用方式对玉米生长和产量的影响,设置启动磷肥大田滴施(T1)、穴施(T2)和不施启动磷肥(CK)3个施肥处理,其中启动肥磷肥用量为P2O5 30 kg·hm-2,探究启动磷肥不同施用方式对玉米生长、养分分配和产量构成的影响;设置启动磷肥根箱土壤滴施(P1)、穴施(P2)和不施启动肥(CF)3个处理,其中启动肥磷肥用量为P2O5 0.2 g·kg-1土,探究启动磷肥施用后土壤中磷素的空间分布与迁移效果。结果表明,玉米四叶期和六叶期,T1和T2处理均显著增加了苗期玉米总根长,根表面积,地上、地下部生物量和N、P、K养分积累量。在六叶期,T1和T2处理玉米总根长较CK分别增加了21.10%和30.35%,根系表面积分别增加了23.48%和29.20%,地上和地下部生物量分别增加了31.24%和52.38%、33.61%和57.81%。与CK相比,T1和T2处理促进了玉米N、P、K养分的积累,同时促进了养分由营养器官向生殖器官的转移。在玉米吐丝期至成熟期,T1和T2处理玉米N、P、K养分转移量较CK分别增加了29.75和44.73 kg·hm-2、10.76和14.65 kg·hm-2、2.20和24.67 kg·hm-2。玉米穗长、行粒数、产量和磷肥偏生产力均表现为T2>T1>CK,玉米穗秃尖长度表现为T2相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2501-2508
Abstract A considerable amount of land enrolled in the Conservation Reserve Program (CRP) has been and will be returned to row crop production. It is difficult to predict how to manage nitrogen (N) fertilizer for these row crops, since there are plausible reasons to expect either substantial N immobilization or substantial N mineralization due to the effects of CRP enrollment. Our objective was to characterize corn (Zea mays L.) yield response to N following CRP in order to develop N management recommendations. Corn was planted either directly into killed CRP sod (CRP‐corn) or following soybean [Glycine max (L.) Merr.] that had been planted into killed CRP sod (CRP‐SB‐corn)‐ We applied a range of N rates and determined the economically optimum N rate from the yield response data. In both years of the study, the optimum N rate for CRP‐corn was much higher (181 and 230 lb N acre‐1 in 1996 and 1997, respectively) than theoptimum N rate for CRP‐SB‐corn(108 and 113 lb Nacre‐1 in 1996 and 1997, respectively). CRP‐corn with no N fertilizer appeared extremely N deficient for the first half of the season. We observed a large flush of inorganic soil N in late summer of the first year out of CRP, but this N was apparently too late for optimum corn production that season. We recommend soybean as the first choice row crop to plant immediately following CRP. If corn is to be planted immediately following CRP, we recommend higher‐than‐normal N rates to optimize production. 相似文献
17.
Paul Hepperly Don Lotter Christine Ziegler Ulsh Rita Seidel Carolyn Reider 《Compost science & utilization》2013,21(2):117-126
From 1993 to 2001, a maize-vegetable-wheat rotation was compared using either 1) composts, 2) manure, or 3) synthetic fertilizer for nitrogen nutrient input. From 1993 to 1998, red clover (Trifolium pratense L.) and crimson clover (Trifolium incarnatum L.) were used as an annual winter legume cover crop prior to maize production. From 1999 to 2001, hairy vetch (Vicia villosa Roth.) served as the legume green manure nitrogen (N) source for maize. In this rotation, wheat depended entirely on residual N that remained in the soil after maize and vegetable (pepper and potato) production. Vegetables received either compost, manure, or fertilizer N inputs. Raw dairy manure stimulated the highest overall maize yields of 7,395 kg/ha (approximately 140 bushels per acre). This exceeded the Berks County mean yield of about 107 bushels per acre from 1994 to 2001. When hairy vetch replaced clover as the winter green manure cover crop, maize yields rose in three of the four treatments (approximately 500-1,300 kg/ha, or 10-24 bu/a). Hairy vetch cover cropping also resulted in a 9-25 % increase in wheat yields in the compost treatments compared to clover cover cropping. Hairy vetch cover crops increased both maize and wheat grain protein contents about 16 to 20% compared to the clover cover crop. Compost was superior to conventional synthetic fertilizer and raw dairy manure in 1) building soil nutrient levels, 2) providing residual nutrient support to wheat production, and 3) reducing nutrient losses to ground and surface waters. After 9 years, soil carbon (C) and soil N remained unchanged or declined slightly in the synthetic fertilizer treatment, but increased with use of compost amendments by 16-27% for C and by 13-16% for N. However, with hairy vetch cover crops, N leaching increased 4 times when compared to clover cover crops. September was the highest month for nitrate leaching, combining high rainfall with a lack of active cash crop or cover crop growth to use residual N. Broiler litter leaf compost (BLLC) showed the lowest nitrate leaching of all the nutrient amendments tested (P= 0.05). 相似文献
18.
[目的]研究新疆卡拉贝利工程区植物防风固沙效果,为该地区的风沙治理措施提供理论依据,[方法]对该地区的植被进行了防风蚀效果的调查研究,主要收集了植被的盖度、冠幅、高度等植被特征和植被积沙特征的数据,采用SPSS等统计软件进行数据的统计分析,并利用曲线估计的方法建立植物形态与积沙量的回归模型,量化分析植物形态特征与植物积沙的关系。[结果]该地区植被以盐爪爪为主,并伴有少量骆驼刺、假木贼等植物;不同砾石覆盖度对植被的密度和盖度影响较大,对植物的高度、冠幅影响较小,且砾石覆盖度越高植被密度和盖度越低;植物积沙量、植物积沙丘的厚度与宽度均随着植物高度和冠幅的增加而呈指数增加;植物形态对积沙量增加的影响程度表现为:植物高度纵向冠幅横向冠幅。[结论]该地区植被具有一定的防风蚀能力,其防风蚀效果的大小与植被的形态以及地表砾石含量存在很大的关系。 相似文献
19.
控释氮肥不同用量对移栽玉米幼苗生长及养分吸收的影响 总被引:3,自引:0,他引:3
通过盆栽试验,研究了控释氮肥不同用量对移栽玉米幼苗生长及养分吸收的影响。结果表明,玉米育苗期内适宜的控释氮素用量可形成健壮幼苗; 其最大安全控释氮素用量为N 200400 mg/plant,该用量下,移栽时单株可携带N 137290 mg。随控释氮肥用量的增加,植株地上部氮素浓度及氮素累积量增加; 磷素的浓度及累积量与控释氮肥的用量没有显著相关性; 控释氮肥的供应抑制了植株对钾的吸收。 相似文献
20.
雅鲁藏布江江当宽谷区固沙措施对流沙理化性质的改良效应 总被引:1,自引:1,他引:0
[目的]分析雅鲁藏布江江当宽谷区流沙治理技术(砾石覆盖+人工植被+围封)对流沙理化性质的改良效应,为区域荒漠化治理工作提供理论指导。[方法]对比分析固沙区和流动沙丘土壤机械组成、有机质和养分等指标开展研究。[结果]采用植物和工程相结合的固沙措施,在流沙表面覆盖砾石、播种固沙植物,并对该区域进行围封后,沙丘表面植被盖度增加,流沙基本固定。与流动沙丘相比,固沙区土壤的黏粒、粉粒明显增多。固沙区土壤的有机质、全氮、碱解氮、全磷、速效磷、速效钾含量比流动沙丘高;尤其是土壤表层0—5cm,分别比流动沙丘高出634.3%,268.0%,506.5%,38.3%,343.8%,66.7%。固沙区0—5cm土层的pH值比流动沙丘降低了11.5%;电导率比流动沙丘增加了268.1%。[结论]该项流沙治理技术(砾石覆盖+人工植被+围封)的固沙和改良土壤理化性质作用明显,适宜在该区推广使用。 相似文献