施肥对菜园土壤养分淋溶流失浓度的影响

利用盆栽种植空心菜和菜心并收集测定土壤渗漏水氮磷钾养分浓度,研究了不同施肥水平对土壤氮磷钾淋溶流失浓度的影响。试验表明,在较大施肥量或化肥当季损失量范围内,土壤渗漏水硝态氮、总磷和钾浓度与氮、磷、钾施肥量或损失量之间呈非线性关系,但在中低施肥量时则表现为线性关系。化肥当季损失量与土壤渗漏水养分浓度呈显著水平的线性正相关,由此提出“双速率转折点”概念用以评价土壤养分流失潜力。当施肥量或化肥当季损失量超过双速率转折点X0后,土壤淋溶排水养分浓度将以非线性形式急剧增加。因此,从环保角度看,施肥量不应超过X0。盆栽试验表明,以化肥当季损失量为基础的灰泥土、灰黄泥土和黄泥土的氮肥X0分别为每盆N 0.35、0.32和0.34 g,磷肥X0分别为每盆P 0.06、0.06和0.09 g,灰泥土和灰黄泥土的钾肥X0则分别为K 0.17和0.18 g;与土壤渗漏水养分浓度为基础所确定的氮、磷、钾X0有显著水平的线性正相关。以环保为目标的氮磷钾用量X0大多数低于以产量为目标的经济施肥量。化肥当季损失量参数较易获得,可作为环保施肥的依据。     

洞庭湖平原菜园土壤养分径流规律及其影响因素

通过定位大田和田间小区试验,研究了不同蔬菜类型及不同施肥结构对菜园土壤养分径流损失的影响。结果表明:菜园土壤养分径流损失以氮为主,钾素次之,磷素最少。种植辣椒作物由于施肥量大于南瓜,氮、磷、钾养分的淋失显著高于南瓜地。白菜地磷、钾养分的淋失显著高于甘蓝地。春、夏季蔬菜地氮、磷、钾养分的淋失高于秋、冬季蔬菜地。在茄子生育前期,当地菜农习惯施肥处理(CK2),氮、磷养分的淋失较其他处理严重,单施化肥处理(NPK),钾养分的淋失较其他处理严重。白菜、甘蓝地前2次径流水样中,习惯施肥和单施化肥处理氮、磷、钾养分的淋失较其他处理严重。施用有机肥料,在蔬菜生育后期氮、磷、钾养分的淋失大于其他处理,维持较高的水平。不施肥处理,也存在着养分的损失,且数量较大,在生产实践中应加强土壤养分资源的管理和高效利用。     

洞庭湖平原冲积性菜园土壤养分径流规律研究

通过定位大田和田间小区试验,研究不同作物类型及不同施肥结构对菜园土壤养分径流损失的影响。结果表明,菜园土壤养分径流损失以氮为主,磷、钾素相对较少。从氮素形态看,以硝态N为主,铵态N较少。就淋失速度而言,硝态N最快,磷素次之,铵态N和钾素较慢且有一定的持续性。种植辣椒作物,由于施肥量大于南瓜,N、P养分的淋失显著高于南瓜地。当地菜农习惯施肥(CK2)和单施化肥处理(NPK),在辣椒生育前期,N、P养分的淋失较其他处理严重。施用有机肥料,特别是饼肥,作物生育后期水溶性总N和硝态N的淋失大于其他处理。不施肥处理,也存在着N、P养分的损失,且数量较大,在生产实践中应加强土壤养分资源的管理和高效利用。     

缓释复合肥料对酸性菜园土壤微生物数量特征的影响

采用盆栽试验研究缓释复合肥料（SRF）对酸性菜园土壤微生物数量特征的影响。两次测定（35d和45d）结果表明,在各处理中,SRF处理土壤微生物量碳（SMBC）含量、细菌和放线菌数量均为最高,其中SMBC达到显著;SRF处理微生物量氮（SMBN）含量显著高于普通复合肥（CCF）处理（分别提高25.8%和38.6%）,真菌数量低于包膜缓释肥（CRF）处理,高于CCF处理;与施用普通复合肥（CCF）处理相比,SRF能够显著提高白菜产量（分别提高16.4%和13.9%）,而与包膜肥料CRF处理无显著差异。     

不同施肥结构对红菜园土有机质、酸性和交换性能的影响

采用田间小区试验研究不同施肥结构和酸调理剂对由第四纪红土发育的酸性红菜园土的有机质、酸性以及交换性能的影响.结果表明,化肥+石灰(NPK+ CaO)和化肥+氧化镁(NPK+ MgO)处理的土壤pH极显著高于其他各处理,并且能显著降低土壤交换态铝的含量,而酸化调理剂2号(NPKSR2)对土壤pH的提高又显著高于其他各处理,土壤pH与土壤交换性铝离子呈负相关;各施肥处理均能提高土壤有机质含量,以化肥+菜枯(NPK+OM)处理效果最佳,该处理土壤有机质含量平均达16.71 g/kg,酸化调理剂2号(NPKSR2)也能显著提高土壤有机质含量;化肥+石灰(NPK+ CaO)和化肥+氧化镁(NPK+MgO)处理提高土壤阳离子交换量(CEC)和有效阳离子交换量(ECEC)效果最显著,酸化调理剂2号(NPKSR2)又优于其他各处理,化肥+氧化镁(NPK+ MgO)处理能有效提高土壤交换性盐基离子各组成的含量;化肥(NPK)和酸化调理剂2号(NPKSR2)处理均能缓慢提高蔬菜作物产量,而其他各处理蔬菜作物产量均不稳定.     

施肥和土壤养分对毛竹笋营养成分的影响

本试验研究了N、P、K肥料和土壤N、P、K养分对毛竹笋营养成份的影响,并由此考察了其营养成份,结果表明,毛竹笋的氨基酸总量和必需氨基酸含量高于一般蔬菜。游离Glu,Gln及Asp是毛竹笋的鲜味成分,其中冬笋主要是Gln和Asp,春笋则是Glu和Asp。施肥提高笋体的水解氨基酸和游离氨基酸含量。糖分含量随氮肥增加而减少,随磷肥增加而增加,钾肥对糖分影响不明显,冬笋水解氨基酸含量与土壤水解氮成显著正相关,而与土壤速效磷及速效钾相关不显著。N、P肥料的施用及高含量的土壤N、P养分有利于笋体游离Tyr的降低。     

施肥对蔬菜中硝酸盐含量的影响

通过对山东省蔬菜面积较大的潍坊和青岛市的蔬菜进行了取样分析及有关的试验，结果表明：依据国家标准(GB18406．1-2001)在所测的所有样品中，蔬菜硝酸盐含量均没有超标。而依据FAO／WHO(1973年)规定，瓜果类和根茎类蔬菜硝酸盐含量均不超标，而叶菜类有近30％超标，超标蔬菜达到了生食盐渍不宜，熟食允许的程度；同一种类蔬菜露天栽培比保护地栽培的硝酸盐积累量少；氮磷钾合理配合施用能减少蔬菜硝酸盐积累。本文提出了控制蔬菜硝酸盐积累的施肥措施。     

长期施肥对酸性土壤磷形态及有效性的影响

为明确长期施肥对集约化果园土壤磷形态、分布特征及其有效性的影响，本研究对琯溪蜜柚主产区29个果园的土壤进行调查研究，采用张守敬和Jackson的酸性土壤无机磷分级方法，研究蜜柚果园土壤磷素累积对土壤磷形态及有效性的影响。结果表明：在集约化蜜柚果园中，土壤磷素累积丰富，随树龄增加土壤速效磷含量上升显著，且土壤磷形态在不同土层存在显著性差异；当全磷含量≤0.5 g/kg时，土壤磷形态主要以有机磷、铁磷为主，随着全磷含量的上升，铝磷含量、占比均显著上升；多元线性回归和逐步回归分析结果表明本试验中铝磷与速效磷相关性最好。果园土壤已经形成一个巨大的磷库，且有效性较高，可适当减少磷肥投入，降低土壤磷含量，减少经济成本，提高生态效益。     

长期施肥对土壤团聚体分布和养分含量的影响

土壤团聚体组成和土壤养分状况是评价土壤肥力的两个重要指标。不同粒级的团聚体在营养元素的保持、供应及转化能力等方面发挥着不同的作用。本文通过比较长期施肥对土壤团聚体的分布和对土壤养分在团聚体分布变化的影响,全面评价长期施肥对改善土壤肥力状况的作用。结果表明：长期施肥减少＞5 mm 的非团粒结构的数量,增加 0.25 ~ 5 mm 团聚体的含量,改善了土壤的物理结构;土壤大团聚体中含有更多的全 C、全 N、全 P,因此大团聚体对养分的保持有重要作用;施肥对速效养分含量影响显著,碱解 N 含量随粒级的减小而增加,有利于作物的吸收;肥料的施加使得小粒级团聚体对土壤养分储量的贡献率越来越突出,更利于养分的供给。此外,研究还发现耕作条件下有机无机肥配施不利于较小粒级团聚体全 N 和全 P 的保持。     

Nitrogen fertilization and nitrate leaching into groundwater on arable sandy soils

Nitrate leaching depending on N fertilization and different crop rotations was studied at two sites with sandy soils in N Germany between 1995 and 2000. The leaching of NO was calculated by using a numerical soil‐water and N model and regularly measured N_min values as input data. Also the variability of N_min values on the sandy soils was determined along transects. They reveal the high variability of the N_min values and show that it is not possible to confirm a significant N_min difference between fertilizer treatments using the normal N_min‐sampling intensity. Nitrate‐leaching calculations of five leaching periods showed that even strongly reduced N‐fertilizer applications did not result in a substantially lower NO leaching into the groundwater. Strong yield reductions of even more than 50%, however, were immediately measured. Mean NO concentrations in the groundwater recharge are >50 mg L^–1 and are mainly due to mineralization from soil organic matter. Obviously, the adjustment of the N cycle in the soil to a new equilibrium and a reduced NO ‐leaching rate as a consequence of lower N inputs need a much longer time span. Catch crops are the most efficient way to reduce the NO concentrations in the groundwater recharge of sandy soils. Their success, however, strongly depends on the site‐specific development possibilities of the catch crop. Even with all possible measures implemented, it will be almost impossible to reach NO concentrations <50 mg L^–1 in sandy soils. The only way to realize this goal on a regional scale could be by increasing areas with lower nitrate concentrations in the groundwater recharge like grassland and forests.     

Growth and nutrient and nitrate accumulation of lettuce under different regimes of nitrogen fertilization

Abstract

For plant growth and composition, the effects of fertilizers including blood meal (BLO), cottonseed meal (CSM), dehydrated cow manure (COW), and urea (UREA) factored with lettuce (Lactuca sativa L.) of different morphological phenotypes including iceberg, romaine, loose head, and loose leaf were studied in a greenhouse. Lettuce growth increased with increasing nitrogen (N) applications from 0 to 800?mg N/pot (kg), but the top application of BLO, CSM, or UREA suppressed yields. Lettuce grown with BLO, CSM, or UREA had higher concentrations of N than with COW. Nitrate-N concentration in leaves of all varieties exceeded some standards at high application of organic fertilizer or urea except for COW. In general, increasing N application resulted in higher concentration of NH₄-N in lettuce with increases in applications of fertilizers. Organic fertilizers and urea were equally effective in supporting growth and affecting nutrient accumulation in lettuce if sufficient N was supplied.     

钼肥对莴苣、油麦菜硝酸盐含量的影响

无论是作底肥还是作追肥，施用钼肥均能显著抑制莴苣、油麦菜的硝酸盐积累。叶类蔬菜施肥应氮、磷、钾合理搭配，并宜作底肥施用；单施氮肥容易导致硝酸盐的大量积累。     

间作对气雾培生菜生长和硝酸盐积累的影响

该文对生菜与樱桃萝卜间作和生菜单作模式下气雾培生菜相关指标进行了对比研究,并结合营养液中矿质元素含量的变化规律进一步分析了生菜与樱桃萝卜间作模式下生菜地上部分硝酸盐积累的主因素。结果表明：生菜与樱桃萝卜间作有利于提高生菜地上部分鲜质量,促进生菜叶片的展开以及生菜植株根总长度、根系表面积和根系体积等植株根系形态学参数的增大;生菜与樱桃萝卜间作增加了生菜SPAD值、净光合速率、气孔导度和蒸腾速率等光合指标,而对胞间CO2浓度无明显规律性影响;生菜与樱桃萝卜间作不同程度地降低了生菜硝酸盐含量,随着气雾培时间的推进,总体呈先降低后增加的趋势,而硝酸还原酶活性的变化趋势与硝酸盐含量的变化趋势相反;进行相关性分析得出,生菜与樱桃萝卜间作模式下生菜硝酸盐含量降低主要是由于硝酸还原酶活性的增加导致的,并且营养液中硝态氮消耗量、铵硝比和锰消耗量对硝酸还原酶活性影响较大,相关系数分别为0.882、0.762和0.851。研究结果揭示了生菜与樱桃萝卜间作模式对气雾培生菜生长和硝酸盐积累的影响,并探究了该模式下生菜硝酸盐积累的主因素,为生菜与樱桃萝卜间作模式的作用机理研究提供一定的理论基础。     

单宁酸对不同pH茶园土壤中活性铝形态分布的影响

采集云南省普洱市和江西省南昌县两地典型的茶园土壤,通过添加HCl和Ca(OH)2调节土壤pH,研究不同pH(3.0、3.5、4.0、4.5)茶园土壤添加0.4 mmol·kg 1、2.0 mmol·kg 1、4.0 mmol·kg 1、8.0 mmol·kg 1、12.0 mmol·kg 1单宁酸后,活性铝形态交换态铝(Al3+)、单聚体羟基铝[Al(OH)2+、Al(OH)+2]、酸溶无机铝[Al(OH)03]和腐殖酸铝[Al-HA]的分布特征。结果表明:单宁酸添加量为0~0.4 mmol·kg 1和0~2.0 mmol·kg 1时,江西南昌和云南普洱茶园土壤中交换态铝随土壤pH的增加呈明显下降趋势,而羟基态铝、酸溶无机铝和腐殖酸铝呈逐渐上升趋势;当单宁酸浓度增至2.0 mmol·kg 1以上时,随土壤pH的增加,单宁酸对活性铝释放的抑制作用增强,各形态活性铝含量都较低,且不同pH处理土壤间的差异不显著。0~20 cm土层土壤与20~40 cm土层土壤变化规律大致相似,总体上看,下层土壤活性铝总量高于上层。云南普洱茶园土壤活性铝总量明显高于江西南昌的茶园土壤。相关分析表明,0~20 cm土层土壤中,pH与羟基态铝、腐殖酸铝、土壤酸碱缓冲容量(pHBC)呈正相关(r=0.796,P0.01;r=0.960,P0.01;r=0.852,P0.01);pHBC与交换态铝、羟基态铝呈负相关(r=0.904,P0.01;r=0.645,P0.05),而与腐殖酸铝呈正相关(r=0.795,P0.01)。同时,单宁酸加入浓度为0~0.4 mmol·kg 1时,土壤pH明显上升,之后随着单宁酸加入浓度的增加土壤pH持续下降,土壤pH(YpH)与单宁浓度(CDN)在此阶段基本符合方程:YpH=0.04CDN+3.82(R2=0.95,P0.01)的线性变化趋势,在单宁酸浓度达到8.0~12.0 mmol·kg 1时,土壤pH基本不再变化。     

Effect of different fertilization modes on soil organic carbon sequestration in acid soils

ABSTRACT

A meta-analysis of 297 treatment data from the Vezaiciai Branch of the Lithuanian Research Centre for Agriculture and Forestry long-term field experiment published from 2006 to 2015 was used to characterize the changes in SOC under different fertilization treatments and residue management practices in Lithuania’s acid soil. A meta-analysis was performed to quantify the relative annual change (RAC) of SOC content and the average RAC rate of SOC under four fertilization modes (farmyard manure (FYM) (40?t?ha^?1)); alternative organic fertilizers (in the manure background (40?t?ha^?1)); FYM (60?t?ha^?1); alternative organic fertilizers (in the manure background (60?t?ha^?1)) in two soil backgrounds (naturally acid and limed soil). The average RAC under four fertilization modes was 1.46 g?kg^?1?yr^?1, indicating that long-term fertilization had considerable SOC sequestration potential. Incorporation of alternative organic fertilizers in unlimed soil showed negative effects (?0.39 and ?0.66 g?kg^?1?yr^?1) in the observed long-term experiment. The RAC in the limed soil with incorporated organic fertilizers (FYM and alternative organic fertilizers), compared to the control, and varied from 0.25 g?kg^?1?yr^?1 in the treatment with incorporated alternative organic fertilizers (in the manure background (40?t?ha^?1)) to 0.71 g?kg^?1?yr^?1 in the soil with FYM (60?t?ha^?1). In this study, the average RAC rate of SOC under organic fertilization treatments in limed soil (5.07–6.54%) was longer than organic fertilization in unlimed soil (2.11–3.49%), which might be attributed to the application of organic manure that would result in a slow release of fertilizer efficiency. Our results indicate that the application of manure (40 or 60?t?ha^?1) showed the greatest potential for C sequestration in agricultural soil and produced the longest SOC sequestration duration.     

Effect of NO3 and NH4 concentrations in nutrient solution on yield and nitrate concentration in seasonally grown leaf lettuce

The effect of suboptimal supply of nitrogen (N) and of replacing nitrate in the nutrient solution with ammonia on growth, yield, and nitrate concentration in green and red leaf lettuce was evaluated over two seasons (autumn and spring) using multiple regression analysis. The plants were grown in a greenhouse on a Nutrient Film Technique (NFT) system. Nitrogen concentrations in the nutrient solution were either 3?mM or 12?mM, and the form of N was varied as follows: 100% NO₃, 50% NO₃?+?50% NH₄, and 100% NH₄. In both seasons, the biomass (fresh weight) of lettuce heads increased with increasing NO₃ concentrations and in autumn, NO₃ even at 1.5?mM was sufficient for high yield. However, head dry weight was affected neither by the season nor by changes in the composition of the nutrient solution. The concentration of NO₃ had no effect on root dry weight, but it decreased at higher concentrations of NH₄. The number of leaves increased as the ratio of NO₃ to NH₄ in the nutrient solution increased and was higher in autumn because of the longer growth period. Increasing the concentration of NO₃ in nutrient solution increased both total N and nitrate concentration in lettuce heads (dry weight) but decreased the concentration of total C. Also, leaf nitrate concentration was lower in spring than in autumn and decreased with increasing NH₄ concentration. Nitrogen utilization efficiency was maximum when NH₄ levels in the nutrient solution were either 0% or 50% irrespective of the season. Our results thus show that suboptimal N supply in autumn will not affect lettuce yield, and that nitrate concentration in leaves is lower when NH₄ concentrations in nutrient solution are higher and also much lower in red lettuce than in green lettuce.     

长期施肥稻田土壤基础地力和养分利用效率变化特征

【目的】 研究长期不同施肥措施对土壤基础地力和氮磷钾养分吸收利用效率的影响,探明土壤基础地力和氮、磷、钾养分吸收利用效率的相互关系。 【方法】 采集双季水稻种植制度下 33 年长期定位施肥试验的不施肥 (CK)、施氮磷钾肥 (NPK) 和氮磷钾肥配施稻草 (NPKS) 3 个处理的土壤,设置施肥与不施肥盆栽试验,监测水稻产量、土壤基础地力产量和基础地力贡献率、水稻氮磷钾养分吸收量、氮磷钾养分利用效率,分析氮、磷、钾利用效率对土壤基础地力贡献率的响应。 【结果】 早晚稻土壤基础地力产量和基础地力贡献率三个处理土壤大小顺序均为 NPKS > NPK > CK,NPKS 处理土壤早晚稻两季平均基础地力产量和基础地力贡献率较 CK 处理土壤分别增加 113.8% 和 93.7%,NPK 处理分别增加 100.7% 和 81.9%。在同一施肥水平条件下,早、晚稻均以土壤基础地力较高的 NPKS 处理氮、磷、钾肥偏生产力,土壤养分依存率,氮、磷、钾素收获指数较高,氮、磷、钾肥回收利用率,肥料农学效率,肥料对产量的贡献率则较低。回归分析表明,氮、磷肥回收利用率,氮、磷、钾肥农学效率,氮、钾素生理利用率均随土壤基础地力贡献率的提高呈显著或极显著降低;氮、磷、钾肥偏生产力,氮、磷、钾素土壤依存率随土壤基础地力贡献率的提高呈显著或极显著提高。 【结论】 长期施氮磷钾肥或长期氮磷钾肥配施稻草均能提高土壤基础地力,以长期氮磷钾肥配施稻草的效果更显著。在较高基础地力土壤上生产,可以在保证作物高产稳产的情况下实现减量化施肥,实现农业生产的可持续性。      

不同氮肥施用模式对日光温室生菜品质及土壤环境影响

研究不同的氮肥施用模式对日光温室生菜品质及土壤环境影响。结果表明:生菜生产应采用以基肥为主的施肥模式,蔬菜施肥两周后采收较安全。氮肥早施对蔬菜品质有利,也避免硝酸盐和亚硝酸盐大量积累,后期追肥过多过晚不利于蔬菜品质提高,也威胁蔬菜和土壤安全,蔬菜生长后期不宜过多追肥。