共查询到19条相似文献，搜索用时 187 毫秒
1.
有机肥施用和外源镉添加对土壤理化性质、油菜生长及其镉积累的影响 总被引：3，自引：0，他引：3
采用盆栽试验方法，研究了施用鸡粪、牛粪、蚯蚓粪对外源添加不同浓度Cd土壤的酶活性等性状、盆栽作物油菜生长及其Cd吸收积累的影响；试验供试土壤Cd添加浓度为0、1、10、50 mg kg?1，以不施有机肥为对照、3种有机肥用量均为4%。结果表明:施用有机肥使土壤有机质含量、酶活性显著提高，施用鸡粪、牛粪处理土壤脲酶、磷酸酶活性最高，施用蚯蚓粪处理土壤的过氧化氢酶活性最高，但土壤pH值受施用有机肥的影响不明显。外源Cd的添加使土壤酶活性下降、且下降幅度与Cd添加浓度成正比；在高浓度添加Cd（10、50 mg kg?1）土壤，与对照相比三种有机肥处理有机结合态Cd比例提高37.6% ~ 117.3%，交换态Cd比例降低了14.7% ~ 28.3%。在Cd添加浓度为0、1、10 mg kg?1土壤，施用有机肥处理与对照相比，油菜叶片叶绿素含量、产量显著提高，且施用鸡粪和牛粪的效果又好于施用蚯蚓粪；而在Cd添加浓度50 mg kg?1土壤，只有施用蚯蚓粪处理油菜的叶绿素含量和产量提高，较未施用有机肥处理分别提高了38.8%和290%。在Cd添加量为10、50 mg kg?1土壤，施用有机肥处理油菜植株体内Cd浓度较未施有机肥处理下降了14.2% ~ 27.7%，而油菜体内Cd含量的降低效果以施用蚯蚓粪处理最好，优于施用鸡粪、牛粪处理。总之，从降低油菜体内Cd含量和提高油菜产量来看，在添加Cd浓度低于10 mg kg?1的土壤，施用鸡粪、牛粪的效果较好，而在添加Cd浓度达到50 mg kg?1的土壤则以施用蚯蚓粪的效果为更好。 相似文献
2.
肥料与石膏配施对滨海盐土油菜生长及养分吸收的影响 总被引：1，自引：0，他引：1
通过盆栽试验,研究了肥料与石膏配合施用对滨海盐土油菜生长及养分吸收的影响,探讨了滨海盐土适宜的肥料品种。结果表明,肥料与石膏配合施用对滨海油菜生长有显著影响,在油菜干物质累积、油菜产量上均以有机无机复混肥、生物有机肥配合无机复混肥配施石膏效果最好。供试肥料品种间,油菜生长中后期在干物质累积、产量上均表现出有机无机复混肥(F2)、生物有机肥配合无机复混肥(F4)>无机复混肥(F1)>生物有机肥(F3)>对照,各肥料较对照分别增产195.6%、190.9%、117.0%和53.4%。在有机无机复混肥、生物有机肥配合无机复混肥的基础上增加石膏的施用量可明显改善油菜生长状况和产量,但在无机复混肥基础上增加石膏施用量会导致油菜干物质累积和产量的明显降低。肥料与石膏配合施用影响油菜对N、P、K养分的吸收,在油菜苗期养分吸收上,N、K以无机复混肥(F1)较高,P以有机无机复混肥(F2)较高,施用石膏可促进油菜对N、K的吸收,但会显著降低对P的吸收量。滨海盐土地区油菜栽培以有机无机复混肥(F2)、生物有机肥配合无机复混肥(F4)配合石膏(B2)施用较为适宜。 相似文献
3.
【目的】揭示生物炭连续添加对旱地红壤溶解性有机碳的影响。【方法】通过定位试验,探讨了低剂量(0.75～1.5 t hm-2)生物炭连续施用7年后油菜产量、土壤理化性质和溶解性有机碳荧光光谱组分及参数变化特征。【结果】与对照(CK)相比,生物炭施用降低了土壤交换性Al3+含量(0.69～0.87 cmol kg-1),提高了土壤pH(0.13～0.21个单位)、有机质含量(11.7%～18.1%)和可溶性碳含量(127.5%～127.8%);油菜单株角果数提高了39.8%～45.2%,油菜产量增加了3.5%～20.3%,其产量随着生物炭添加量呈递增趋势。连续施用生物炭有利于增加溶解性有机碳中类酪氨酸和类富里酸的比例,且显著降低了微生物代谢产物的比例。与CK相比,连续施用生物炭后土壤溶解性有机碳荧光指数降低了4.4%～10.6%,新鲜度指数降低了17.4%～18.4%,自生源指数降低了0.26(22.6%),而腐殖化指数增加了1.2%～5.1%。相关分析表明溶解性有机碳与pH呈显著正相关,而与交换性Al3+呈显著负相关;微生物代谢产物与pH呈显著... 相似文献
4.
林素兰 《水土保持应用技术》2011,(5):4-5
采用模拟侵蚀降雨对胡伯根(Hoberg)和布鲁塞尔(Brussels)土壤不同深度施用PAM、石膏或二者混施的土壤侵蚀进行了探索,试验结果表明施用PAM、石膏或二者混施,不同质地、不同深度的土壤延缓初始产流时间、降低径流量和冲刷量明显不同,施用20 kg/hm2 PAM溶液、40 kg/hm2 PAM溶液、20 kg/hm2 PAM溶液+5 t/hm2干石膏延缓了有机质含量≤0.15%土壤的初始产流时间,施用5 t/hm2干石膏延缓有机质含量低(0.2%)的酸性(pH=4.1)土壤的初始产流时间。施用20 kg/hm2 PAM溶液+5 t/hm2干石膏平均减少径流量25%,平均减少冲刷量47%(除有机质含量3.7%的土壤外)。各处理减少径流量和冲刷量的顺序为20 kg/hm2 PAM溶液+5 t/hm2干石膏>40 kg/hm2 PAM溶液>20 kg/hm2 PAM溶液>5 t/hm2干石膏,施用20 kg/hm2 PAM溶液+5 t/hm2干石膏效果最好。 相似文献
5.
湖北四种典型土壤硫肥效应 总被引：3，自引：0，他引：3
选择黄棕壤、红壤、灰潮土和水稻土等湖北省四种主要土壤类型,对油菜和水稻分别进行盆栽和田间硫肥试验。试验结果表明:黄棕壤、红壤和灰潮土三种土壤盆栽油菜施用硫肥后,均能促进油菜的生长发育并增加油菜的干物重,但总体上施石膏的效应比施硫磺要好。水稻土田间水稻硫肥试验后,明显提高了水稻产量,但施硫磺粉的效果要比施石膏好,前者的增产率达到27.44%,后者是14.88%。试验前后土壤有效硫的变化进一步说明施用硫肥可以维持土壤硫素平衡,满足作物营养需求。使用澳大利亚KC l—40方法测定土壤有效硫含量,能反映土壤供硫水平与作物产量的相关性,这对于指导我国农业生产具有重要的意义。 相似文献
6.
选择长江流域油菜产区研究安徽省土壤缺S现状和油菜植株硫营养状况。结果表明,安徽省长江流域油菜产区,土壤有效S平均含量15.31mgkg-1,缺S状况较为严重,缺S土壤所占比例高达63.10%,潜在性缺S土壤所占比例为35.48%。主要土壤类型中灰潮土缺S状况最为严重,有效S不足的土壤所占比例高达80%。油菜植株全S含量为5.08~20.18gkg-1,平均10.02gkg-1。花和叶含S量较高,全S含量平均为11.06gkg-1和11.00gkg-1,茎杆含S量较低,全S平均含量仅8.00gkg-1。油菜花朵和叶片全S含量多在8~16gkg-1,茎杆含S量在6~10gkg-1之间。花、叶、茎全S含量(y)与土壤有效S含量(x)之间呈极显著二次曲线正相关,回归方程分别为y1=3.79782+0.88501x-0.02265x2(R2=0.4156**,F=9.96,n=31),y2=3.6548+0.86280x-0.02111x2(R2=0.26569**,F=5.07),y3=3.78016+0.45330x-0.00981x2(R2=0.34399**,F=7.32)。 相似文献
7.
生物质炭对黑土硝态氮淋失的影响 总被引：2，自引：0，他引：2
为探究不同类型和不同用量生物质炭对黑土硝态氮(NO_3~-—N)淋失的影响,采用室内土柱模拟法进行淋溶试验,探究了3种来源(玉米秸秆、稻壳、松木)和4个添加比例(0.6%,1.2%,3.6%,6%)的生物质炭对黑土淋溶液的pH、电导率(EC)、体积、淋溶液中NO_3~-—N浓度及土壤NO_3~-—N淋失量的影响。结果表明:淋溶液的pH和EC与生物质炭的施用量呈正比,且3种生物质炭对淋溶液pH的影响表现为玉米秸秆稻壳松木;对淋溶液EC的影响表现为稻壳松木玉米秸秆。淋溶液体积与生物质炭的施用量呈反比,CK处理中累积淋溶液体积为2 530ml,玉米秸秆、稻壳和松木生物质炭的各处理中均为6%处理的累积淋溶液体积最低,分别比CK降低了16.91%,10.77%和10.70%。施用生物质炭可降低淋溶液中NO_3~-—N浓度,CK处理中淋溶液NO_3~-—N浓度范围为38.09~5.02 mg/L,玉米秸秆生物质炭中1.2%处理的淋溶液NO_3~-—N浓度最低,范围为21.31~0.74mg/L;稻壳、松木生物质炭中3.6%处理的淋溶液NO_3~-—N浓度最低,范围分别为21.86~1.06mg/L和22.76~1.11mg/L。施用生物质炭降低了土壤NO_3~-—N淋失量,不同生物质炭对其影响表现为玉米秸秆稻壳松木,当玉米秸秆生物质炭的添加比例为1.2%,稻壳及松木制备的生物质炭添加比例为3.6%时,土壤NO_3~-—N淋失量最低。因此,向黑土中施用生物质炭可以增加淋溶液的pH和EC,降低淋溶液体积和其中所含NO_3~-—N的浓度,从而减少了土壤中NO_3~-—N的淋失量。 相似文献
8.
研究在等氮条件下有机无机肥配施及添加硝化抑制剂DMPP(3,4-二甲基吡唑磷酸盐)对蔬菜产量、品质及土壤硝态氮淋失的影响,旨在为蔬菜安全生产和地下水环境质量保护提供理论依据。采用大型原状土柱系统,连续种植3季蔬菜(蕹菜、苋菜和萝卜),以施有机肥的氮素量占总氮施用量的质量分数为依据,设置8个施肥处理:不施肥(CK)、纯化肥(CF)、30%有机肥+70%无机肥(30%OM)、50%有机肥+50%无机肥(50%OM)、70%有机肥+30%无机肥(70%OM)、纯化肥+DMPP(CF+DMPP)、30%有机肥+70%无机肥+DMPP(30%OM+DMPP)和50%有机肥+50%无机肥+DMPP(50%OM+DMPP)。结果表明:1)随有机肥施用比例增大,蔬菜产量呈下降趋势,但施用比例不高于50%时产量下降不显著;随有机肥施用比例增大土壤硝态氮淋失量及蔬菜硝酸盐均降低,50%OM处理土壤淋失液硝态氮平均浓度及淋失量较CF处理显著降低了29.29%和25.39%,氮肥表观利用率及表观淋失率分别为22.60%和8.82%。2)硝化抑制剂DMPP对蔬菜产量和硝酸盐含量的影响与蔬菜种类和种植季候密切相关,降低土壤硝态氮淋失的效果为CF+DMPP30%OM+DMPP50%OM+DMPP,但DMPP的抑制效果会随有机肥的比例增加而降低。50%OM+DMPP处理氮肥表观淋失率和表观利用率分别为4.70%和26.26%。3)试验期间,3季蔬菜水分输入(降雨和灌溉)分别为总水分输入量的49.82%(蕹菜季)、23.03%(苋菜季)和27.15%(萝卜季);水分淋失量为总淋失量的46.75%(蕹菜季)、19.66%(苋菜季)和33.59%(萝卜季);硝态氮淋失量为总淋失量的73.77%(蕹菜季)、2.31%(苋菜季)和23.92%(萝卜季)。研究表明,50%OM+DMPP处理,是保证蔬菜产量品质,同时有效降低土壤硝态氮淋失量的最优处理;降雨和施肥措施是影响土壤硝态氮淋失的重要因素,合理配施有机肥及添加DMPP并根据蔬菜生长需肥特性进行施肥能有效应对连续降雨造成的硝态氮大量淋失。 相似文献
9.
以内蒙古河套灌区典型的盐碱土为研究对象,采用烟气脱硫石膏、腐殖酸、保水剂材料研发的复合调理剂对根区盐碱土进行综合改良,通过室内盆栽试验,分析不同配比烟气脱硫石膏型复合调理剂对土壤pH值、碱化度、全盐、盐基离子含量、养分水平、含水量、硬度及向日葵出苗率的影响。结果表明:(1)不同比例施用烟气脱硫石膏型复合调理剂后土壤pH值均显著降低,降低幅度0.45～0.79个单位,土壤中Na~+和CO_3~(2-)+HCO_3~-含量分别降低了9.7%～20.1%和14.3%～30.4%;(2)不同比例施用烟气脱硫石膏型复合调理剂后土壤有机质、碱解氮和含水量分别增加了13.9%～119.3%、9.1%～159.2%和4.4%～20.2%,土壤硬度降低了13.4%～56.7%;(3)不同比例施用烟气脱硫石膏型复合调理剂后,向日葵出苗率从6.7%增加到了20.0%～66.7%;通过对盐碱土综合改良效果及向日葵出苗率进行分析,烟气脱硫石膏型复合调理剂的最优配方为烟气脱硫石膏2 580 kg·hm~(-2)、腐殖酸774 kg·hm~(-2)、保水剂516 kg·hm~(-2)。 相似文献
10.
生物质炭对旱地红壤理化性状和作物产量的持续效应 总被引：6，自引：3，他引：3
以江西进贤旱地红壤为供试土壤,连续3a观测施用生物质炭(0t/hm2,2.5t/hm2,5t/hm2,10t/hm2,20t/hm2,30t/hm2和40t/hm2)后土壤容重、孔隙度、饱和导水率、土壤pH、有机碳、阳离子交换量及油菜和红薯产量的变化。结果表明:生物质炭连续3a降低土壤容重,提高了土壤孔隙度和土壤饱和导水率,提升了土壤pH,增加了土壤有机碳和阳离子交换量;油菜和红薯产量均随生物质炭施用量的增加而增加,且红薯产量增幅大于油菜。随种植年限的延长,作物产量增幅越大。高施用量(40t/hm2)处理在旱地红壤上的改良效果和增产效应最好,施用生物质炭后第3a其土壤容重下降了0.17g/cm3,土壤孔隙度和饱和导水率分别增加了11.71%和126.57%,土壤pH、有机碳和阳离子交换量分别提高了7.25%,47.88%和44.61%,油菜和红薯产量分别增加了1.23t/hm2和14.83t/hm2。在连续3a内,旱地红壤施用生物质炭对改善土壤理化性状,维持作物增产具有持续效应,为生物质炭在红壤地区的大规模推广应用提供了科学依据。 相似文献
11.
利用高寒草甸生荒地进行当归育苗的传统方式造成严重的水土流失。为了探讨农茬口调控土壤特性继而影响后茬当归育苗的效应,在道地产区甘肃省卓尼县熟地培育农作物茬口后进行当归育苗,测定育苗期土壤特性、成苗数和产量。结果表明,农茬口对后茬当归育苗田土壤特性具有显著影响,与休耕茬田比较,马铃薯、油菜、蚕豆茬田土壤电导率极显著降低, pH显著提高,青稞茬田土壤pH和电导率均降低,农茬口极显著提高了后茬土壤阳离子含量,降低了阴离子含量。各茬口土壤K~+含量依次为青稞蚕豆油菜马铃薯休耕, Na~+含量为马铃薯青稞蚕豆油菜和休耕, Cl~-含量为休耕马铃薯青稞油菜蚕豆。随土层加深,紧实度增加,孔隙度减少,含水量随土层和茬口而异。0～15 cm土层的土质疏松且含水量高则有利于保苗。当归成苗数和苗产量与土壤电导率、Cl~-含量均呈显著负相关;苗产量与pH、K~+含量呈显著正相关,与5～10 cm土层容重呈显著负相关;苗数与0～5 cm土层总孔隙度呈显著正相关。各茬口育成苗产量排序与综合评价指数顺序一致,综合评价指数依次为蚕豆(0.986)油菜(0.682)青稞(0.668)马铃薯(0.297)休耕(0.159)。因此,优异的茬口特性可优化当归幼苗赖以生存的农田土壤环境,改善土壤性质,富集营养,促生保苗,蚕豆茬口更为优异。 相似文献
12.
中国南方黄泥田土壤中养分淋失严重,尤其是氮(N)和钾(K),不仅造成资源浪费和潜在环境威胁,还严重制约作物的可持续生产。采用室内土柱模拟培养,研究尿素(U)和尿素硝铵(UAN)中单独添加脲酶抑制剂N-丁基硫代磷酰三胺(NBPT)和硝化抑制剂2-氯-6-(三氯甲基)吡啶(CP),及两者配合施用对黄泥田土壤中K素淋溶特征的影响,探讨提高黄泥田供钾能力的施肥技术。不同氮肥种类淋溶液中,K~+平均浓度大小表现为UAN处理(103.0 mg·kg~(-1))高于U处理(93.9 mg·kg~(-1)),且抑制剂处理间存在明显差异。培养结束时(第72 d),UAN处理K~+淋失量较U处理高6.7%。U各处理淋溶液中K~+累积量大小表现为UU+NBPTU+NBPT+CPU+CPCK,其中U+NBPT、U+CP和U+NBPT+CP处理较U处理分别降低8.7%、20.2%和14.9%;UAN各处理淋溶液中K~+累积量表现为UANUAN+NBPTUAN+NBPT+CPUAN+CPCK,其中UAN+NBPT、UAN+CP和UAN+NBPT+CP处理较UAN处理分别降低6.0%、13.8%和9.2%。不同施肥处理K~+淋溶率表现为UANUAN+NBPTUUAN+NBPT+CPUAN+CPU+NBPTU+NBPT+CPU+CP。培养中期(第36 d),U和UAN处理肥际微域中土壤速效钾含量显著降低,而添加CP处理有效维持土壤中较高的速效钾含量。与单施NBPT相比,配施CP可以减少黄泥田土壤中NO_3~-淋溶,增加土壤晶格对K~+的固定,减轻K~+淋溶风险,有效时间超过72 d。对各处理淋溶液中K~+累积量(y)随NO_3~-累积量(x)的变化进行拟合,其中以线性方程(y=ax+b)和Elovich方程(y=alnx+b)的拟合度最高,且抑制剂处理间a、b值均存在明显差异。总之,在黄泥田土壤中单施CP,或与NBPT配施可以有效增加K~+吸附,降低土壤中K~+淋溶损失,减轻养分淋失风险,提高肥料利用率。 相似文献
13.
Mixtures of fine bauxite refining residue (red mud), waste gypsum and local sandy soil that are proposed to be used in a catchment nutrient management program, were watered in columns simulating rainfall over a period of 2 yr and the quality of the leachate determined. The major salts released were sodium sulphate, a product of red mud alkalinity neutralization by gypsum, and excess gypsum released at its solubility concentration. At an application rate of 850 t ha?1 of red mud the salts leached to groundwater (40 kg t?1 red mud) would be equivalent to salts leached by rainfall over a 20 yr period from soil without red mud application, and would pose no significant impact when applied to the sandy agricultural soils in the catchment area of an estuary. The leaching of Al, Fe, and Cd from the red mud and gypsum was negligible, while the retention of superphosphate was over 99%. Fluoride from the waste gypsum was leached rapidly and reduced to background concentration (less than 1 mg L?1) within one winter rainfall. 相似文献
14.
Saline–sodic and sodic soils are characterized by the occurrence of sodium (Na+) to levels that can adversely affect several soil properties and growth of most crops. As a potential substitute of cost‐intensive chemical amelioration, phytoremediation of such soils has emerged as an efficient and low‐cost strategy. This plant‐assisted amelioration involves cultivation of certain plant species that can withstand ambient soil salinity and sodicity levels. It relies on enhanced dissolution of native calcite within the root zone to provide adequate Ca2+ for the Na+ Ca2+ exchange at the cation exchange sites. There is a lack of information for the Na+ balance in terms of removal from saline–sodic soils through plant uptake and leaching during the phytoremediation process. We carried out a lysimeter experiment on a calcareous saline–sodic soil [pH of saturated soil paste (pHs) = 7.2, electrical conductivity of the saturated paste extract (ECe) = 4.9 dS m−1, sodium adsorption ratio (SAR) = 15.9, CaCO3 = 50 g kg−1]. There were three treatments: (1) control (without application of a chemical amendment or crop cultivation), (2) soil application of gypsum according to the gypsum requirement of the soil and (3) planting of alfalfa (Medicago sativa L.) as a phytoremediation crop. The efficiency of treatments for soluble salt and Na+ removal from the soil was in the order: gypsum ≈ alfalfa > control. In the phytoremediation treatment, the amount of Na+ removed from the soil through leaching was found to be the principal cause of reduction in salinity and sodicity. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
15.
Jingzhen Cui Duanwei Zhu Shuijiao Liao Guanglong Liu Liying Ren Wenbing Zhou 《Journal of plant nutrition》2013,36(13):1923-1936
Rape (Brassica napus L.) seedling pot experiments were performed with a red soil treated with goethite which had boron (B) either adsorbed (ad-B-goethite) or occluded (oc-B-goethite). Soil acidity, different forms of manganese in the soils and different elements content of the rape seedlings were determined. It was found that the addition of boron-containing goethite to the soils resulted in increased rape growth, elevated soil pH and decreased exchangeable acidity. Compared with the control, boron-containing goethite elevated the content of exchangeable manganese (Mn) (EXC-Mn), organic matter bound Mn (OM-Mn), reducible oxide Mn (RO-Mn) and residual Mn (RES-Mn) which were difficult to use for plant. Low labile organic matter was significantly correlated with easily reducible oxide Mn (ERO-Mn) (P < 0.01) and RO-Mn (P < 0.05). Middle organic matter and soil pH was significantly (P < 0.05) correlated with RES-Mn. Stepwise regression was used to select the combination of variables that best estimates shoot and root dry weight of rape seedling. Among them, soil pH, EXC-Mn, OM-Mn, RO-Mn and RES-Mn significantly influenced the dry weight of rape seedlings. The addition of boron-containing goethite improved the uptake of iron (Fe), calcium (Ca), magnesium (Mg), and copper (Cu) element and decreased the uptake of Mn and zinc (Zn) element in rape seedling. The results suggested that boron-containing goethite could provide a better soil acidity environment for plant growth; it was also an important agent increasing a part of manganese difficult to use for plant and reducing the activity of soil manganese, which was beneficial to altering rape seedling growth. 相似文献
16.
Acidified precipitation may affect the productivity of forests by altering the availability of plant nutrients or by affecting the ability of trees to absorb and assimilate those nutrients. In this study, the short-term effects of simulated acid rain (pH range 5.6 to 2.3) upon the growth and nutrient relations of Eastern White Pine seedlings (Pinus strobus, L.) grown in a sandy loam soil were examined. Soil chemistry, soil leachate chemistry, seedling tissue chemistry, and seedling productivity were monitored. Inspite increased leaching of cations from the soil, resulting in near depletion of available K+1, Mg+2, and Ca+1 at pH 2.3, seedling productivity increased with acidity through the 20-week experimental period. Foliar nitrogen concentrations indicate that fertilization with NO 3 ?1, added to the rain as HNO3, may have caused the growth increase. Implications of cation losses and NO3 ?1 fertilization are discussed. 相似文献
17.
Jining Zhang Huifeng Sun Jia Ma Xianxian Zhang Cong Wang Sheng Zhou 《Soil Use and Management》2023,39(2):729-741
Intensive vegetable crop systems are rapidly developing, with consequences for greenhouse gas (GHGs) emissions, nitrogen leaching and soil carbon. We undertook a field trial to explore the effect of biochar application (0, 10, 20 and 40 t ha−1) on these factors in lettuce, water spinach and ice plant rotation. Our results show that the 20 and 40 t ha−1 soil treatments resulted in the SOC content being 26.3% and 29.8% higher than the control (0 t ha−1), respectively, with significant differences among all treatments (p < .05). Biochar application caused N2O emissions to decrease during the lettuce and water spinach seasons, by 1.5%–33.6% and 12.4%–40.5%, respectively, compared the control, with the 20 t ha−1 application rate resulting in the lowest N2O emissions. Biochar also decreased the dissolved nitrogen (DN) concentration in leachate by 9.8%–36.2%, following a 7.3%–19.9% reduction in dissolved nitrogen in the soil. Similarly, biochar decreased the nitrate (NO3−) concentrations in leachate by 3.9%–30.2%, following a 3.8%–16.7% reduction in the soil nitrate level. Overall, straw biochar applied at rate of 20 t ha−1 produced the lowest N2O emissions and N leaching, while, increasing soil carbon. 相似文献
18.
Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha~(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha~(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha~(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha~(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching. 相似文献
19.
Three years of N application to a Cambic arenosol (Typic Udorthent) in two lysimeter series, one with and one without young saplings of Pinus sylvestris L. have produced significant changes in soil solution and leachate chemistry. An application of 30 kg N/ha*yr?1 significantly increased NO3 ? leaching from the soil. This N load was also sufficient to significantly increase the mobility of the phyto-toxic elements Al3+ and Mn2+, likewise to increase leaching of the important plant nutrients Ca2+, Mg2+ and K+. At a N load of 90 kg N/ha*yr?1 significant increase in NH4 + leaching was observed, but total leaching of NH4 + was still very low compared to NO3 ? leaching. No significant treatment effects were found for SO4 2?, Fe2+ and Cl? in the leachate. Trees grown in the lysimeters buffered the acidifying effect of N application and increased the leachate pH by 0.2 pH units compared to lysimeters without trees. 相似文献