大尺度冬小麦-夏玉米微喷灌精准自动施肥增产效应

为了明确微喷灌精准自动施肥对冬小麦-夏玉米产量、产值、生产成本效益等的影响,该文以传统施肥技术为对照,设置6.67 hm~2大尺度微喷灌精准自动施肥在冬小麦-夏玉米上的应用效果试验,定量分析微喷灌精准自动施肥对冬小麦和夏玉米产量、产值、生产成本、效益、氮磷用量和灌溉量等方面的影响。结果表明:大尺度冬小麦-夏玉米微喷灌精准自动施肥具有增产、增收、节约成本、节肥、节水的良好应用效果。与传统施肥相比,微喷灌精准自动施肥在冬小麦季显著提高小麦产量,增产10.6%,增加效益43.77%,降低生产成本26.17%,减少氮磷化肥24.20%,节约灌溉用水57.45%。微喷灌精准自动施肥在夏玉米季显著增加玉米产量,增产13.73%,增加效益13.73%,降低生产成本17.09%,减少氮、磷养分用量20.34%,节省灌溉用水36.94%。微喷灌精准自动施肥在冬小麦-夏玉米轮作季增产12.26%,增收效益37.39%,降低生产成本21.85%,减少氮磷化肥22.26%,节省灌溉用水46.51%,具有良好的经济效益和生态效益。研究结果可为该技术的推广提供参考依据,促进农业生产力和农业可持续发展。     

施氮量对潮土区冬小麦-夏玉米轮作农田氮磷淋溶的影响

潮土是我国华北地区主要土壤类型之一,潮土区是我国冬小麦-夏玉米作物的主要产区,研究不同施氮量潮土氮磷淋溶特征对于指导区域农田面源污染防控具有重要意义。本研究设置3个施肥处理,即传统施氮(CON)、优化施氮(OPT)和优化再减氮(OPTJ),利用田间渗漏池法,研究潮土冬小麦-夏玉米轮作农田硝态氮及总磷淋溶特征。结果表明:2016—2018年,冬小麦-夏玉米轮作周年不同施肥处理90cm土层年淋溶水量79.0～102.5 mm,不同淋溶事件间土壤淋溶液硝态氮浓度波动较大, CON、OPT和OPTJ处理单次淋溶事件硝态氮浓度分别为18.9～208.7(平均为72.7) mg·L~(-1)、9.0～99.2 (平均为33.8) mg·L~(-1)、4.7～55.5 (平均为15.4) mg·L~(-1)。本研究区域冬小麦-夏玉米轮作模式的氮素淋溶风险较高,磷素淋溶风险较低。传统施氮处理(CON)下农田硝态氮的平均淋溶量和表观淋失系数分别为66.4 kg·hm~(-2)和10.3%,而总磷(TP)为0.06 kg·hm~(-2)和0.04%。氮肥减施会显著降低氮素淋失,OPT和OPTJ处理的氮素淋溶减排率可达56.3%和78.9%。两个年度CON、OPT和OPTJ处理硝态氮平均表观淋失系数分别为10.3%、6.2%和4.9%,随着施氮量的增加,硝态氮淋失系数动态增加。氮淋溶具有较大的年际变化,降雨量高的2018年比降雨少的2017年硝态氮淋溶量多57.0%。两个年度CON、OPT和OPTJ处理总磷平均淋溶量分别为0.06 kg·hm~(-2)、0.06 kg·hm~(-2)和0.08 kg·hm~(-2)。适量减施氮肥会增加作物产量, OPT处理的作物产量是CON处理的1.08倍。然而,过量减施则会带来减产风险, OPTJ处理氮肥减施56%,作物产量比CON处理降低2.0%～8.1%。总之,潮土区农田硝态氮淋溶风险较大,适量减施氮肥能够在保证作物产量的基础上显著降低氮素淋失损失。     

冬小麦-夏玉米轮作体系中磷钾平衡的研究

对高肥力土壤大量施用磷钾肥冬小麦 /夏玉米轮作周期中作物产量、磷钾养分平衡等进行了研究。结果表明 ,高肥力土壤上连续大量施用磷钾肥条件下 ,传统施氮与优化施氮、秸秆还田与秸秆不还田对冬小麦和夏玉米产量、磷钾吸收量均无显著差异。在一个轮作周期中 ,冬小麦、夏玉米吸磷 (P)量分别为 22～25、18～19kg/hm2;吸钾(K)量分别为 14.7～16.6、96～112kg/hm2。在一个轮作周期后 ,土壤中的速效磷、速效钾含量变化不大。在施用磷肥 (P) 79kg/hm2 的条件下 ,无论秸秆还田与否磷素都有盈余 ,秸秆还田磷素 (P)盈余量为 46～47kg/hm2,秸秆不还田为 36～37kg/hm2;在施用钾肥 (K)75kg/hm2条件下 ,秸秆还田钾素 (K)盈余量为 22～31kg/hm2,秸秆不还田钾素 (K)亏缺量为 168～201kg/hm2,说明秸秆还田对于磷素与钾素特别是钾素的平衡有很大的作用     

氮磷钾平衡施肥对夏玉米产量及养分吸收和累积的影响

结合目前夏玉米施肥存在的种种弊端,探讨平衡施肥对夏玉米产量及养分吸收的影响,为实现夏玉米超高产和合理施肥提供理论依据。通过设置大田试验,研究了不同施肥模式对夏玉米产量、氮肥利用率及养分吸收、累积的影响。氮磷钾平衡施肥(NPK)对夏玉米籽粒产量有显著的增产作用,产量达6426 kg/hm2,分别比PK、NK、NP、FP、CK处理增产13.2%、12.9%、19.3%、12.0%、22.9%。夏玉米生物量累积曲线与N、P、K养分累积曲线基本一致,都呈"S"型,养分累积量的次序为N>K>P,生物量和养分累积主要集中在喇叭口期以后。氮、磷、钾平衡施用可提高夏玉米产量、氮肥利用率以及养分的吸收,在喇叭口期追施肥料值得推广。     

冬小麦-夏玉米轮作产量与氮素利用最佳水氮配置

【目的】华北太行山前平原高产限水区冬小麦-夏玉米轮作体系中灌水施肥不合理的现象普遍存在,水资源浪费和农业面源污染严重。长期定位研究水氮配置对小麦玉米产量和氮素利用影响,可为该区优化水氮管理模式,充分发挥水氮协同增效作用提供依据。【方法】2006~2014年进行大田试验,采取裂区设计,灌水量为主区,施氮量为副区。小麦季灌水设春灌一次水(W1, 拔节水)和两次水(W2, 拔节水+开花水)两个处理; 玉米季在小麦灌一次水基础上设限水处理(WL),在两次水基础上设适水处理(WS),限水和适水的灌水次数根据降水年型而定。两种灌水条件均设置6个施氮水平,分别为0(N0)、 60(N60)、 120(N120)、 180(N180)、 240(N240)、 300(N300)kg/hm2。连续8年定位测定了小麦玉米产量、 植株吸氮量。【结果】小麦玉米产量和植株吸氮量年际间差异均较大,相对而言,W2(WS)产量和吸氮量的年际波动较小,一定程度上降低了不同年型气象因素的影响,达到稳产的效果。两种水分条件下N0 和N60处理的作物产量和吸氮量除个别年份外都显著低于其余施氮处理。本研究的产量水平下(冬小麦7000~9500 kg/hm2,夏玉米8500~11000 kg/hm2)小麦玉米产量与其吸氮量呈显著线性正相关。小麦玉米8年平均产量和吸氮量在一定施氮范围内均随施氮量的增加而显著增加,但施氮达到120 kg/hm2后产量不再显著增加,达到180 kg/hm2后吸氮量不再显著增加,同一施氮水平的作物产量和吸氮量都表现W2(WS)高于W1(WL)。两种水分条件下小麦玉米的氮肥偏生产力、 氮肥农学效率和氮素生产效率都随施氮量的增大而显著减小,但对同一施氮水平W2(WS)高于W1(WL)。冬小麦-夏玉米整个轮作体系氮肥累计表观利用率(一段时期内作物对肥料氮的累计吸收量与该时期施氮总量的比值)同样随施氮量的增加显著减小,一次水+限水条件下从N60+60的51.8%下降到N300+300的22.3%,两次水+适水从N60+60的57.4%下降到N300+300的24.6%。同一施氮水平的氮肥累计表观利用率两次水+适水都高于一次水+限水。【结论】冬小麦春灌两次水、 施用N 120 kg/hm2,夏玉米适水灌溉、 施N 120 kg/hm2的产量和吸氮量都达到最高水平,氮肥偏生产力、 农学效率、 累计表观利用率以及氮素生产效率也比较高,因此在一定时期内可作为当地小麦-玉米轮作体系适宜的水氮配置,周年产量可维持在16~19 t/hm2。     

基于Meta分析的关中平原冬小麦-夏玉米施氮/磷增产效应研究

为明确施用氮肥和磷肥对关中平原冬小麦/夏玉米产量的影响及其控制因素,以公开发表的试验数据为基础,采用Meta分析法定量分析了施氮及施磷条件下,试验年份、作物品种、生育期降水量、种植密度、施氮量、灌水量、土壤质地、施磷量以及施磷比例对冬小麦-夏玉米轮作体系作物产量的影响.结果表明,就试验年份来讲,2007年以后施氮的增产...     

免耕夏玉米施肥方式初探

试验分析了５种免耕播种夏玉米施肥方式对植株体内叶绿素含量、植株形态构成,产量及其形成相关因素的影响。结果表明,不等距间施肥方式效果最好,吉绿素含这３．９４ｍｇ／ｇ,不同时期叶面积均最高,有利于全苗垃苗,增强抗旱能力６,夏玉米产量最高达７６４６４．３ｋｇ／ｈｍ＾２,增产幅度为３５．２３％。     

甘薯氮磷钾肥平衡施用效应分析

本文运用311-A拟饱和最优回归设计,在沿海赤砂土甘薯主产区设置晚薯施用氮磷钾肥料试验,模拟出甘薯薯块产量和施肥利润的氮磷钾肥料效应函数,通过极值判别均为典型函数,用边际分析寻优,获得甘薯薯块最高产量和最高施肥利润的优化施肥组合分别为:Zmax为Z1=N136 25kg/hm2,Z2=P2O552 71kg/hm2,Z3=K2O275 68kg/hm2,薯块产量最高,^ymax=39 214t/hm2;Zopt为Z1=N117 09kg/hm2,Z2=P2O546 24kg/hm2,Z3=K2O247 01kg/hm2,施肥利润最佳为^πopt=18298 99元/hm2。     

生态平衡施肥模型理论与应用

根据质量守恒定律和肥料—土壤—作物间养分转化关系,提出施肥机理模型的一般数学表达式:W=P+Lfsp+(Tn+1-Tn)×2.25(或0.15),称之为“生态平衡施肥模型”.初步应用结果表明,按此模型推荐的施肥量比目标产量法减少17%～22%.     

优化施肥条件下华北冬小麦/夏玉米轮作体系的土壤氨挥发

采用密闭室间歇通气法研究优化施肥条件下华北冬小麦/夏玉米体系的土壤氨挥发损失。结果表明,肥料氮素氨挥发损失主要发生在施肥后的14 d 内, 冬小麦和夏玉米两个生长季氨挥发损失总量及其损失率均表现出随施氮量的降低而降低,玉米季氨挥发损失高于小麦季。习惯施肥小麦季和玉米季氨挥发总量是氮肥减量后移的2.28和2.03倍,而氮肥减量后移处理的小麦和玉米产量显著高于习惯施肥。氮肥后移可节省氮肥30%,是降低氨挥发损失的理想施肥方式。     

Global patterns of soil phosphatase responses to nitrogen and phosphorus fertilization

Hydrolysis of organic phosphorus(P) by soil phosphatases is an important process of P cycling in terrestrial ecosystems, significantly affected by nitrogen(N) and/or P fertilization. However, how soil acid phosphatase(ACP) and alkaline phosphatase(ALP) activities respond to N and/or P fertilization and how these responses vary with climatic regions, ecosystem types, and fertilization management remain unclear. This knowledge gap hinders our ability to assess P cycling and availability from a glo...     

Rabbiteye blueberry plant response to nitrogen and phosphorus

Acid, sandy soils selected for blueberry production are usually deficient in plant available phosphorus. Fertilizer addition at planting has not been a recommended practice. This research was designed to evaluate potted blueberry (Vaccinium ashei Reade) plant growth response to P applied at establishment and interacted with N applied during the growing season. Four liter containerized ‘Tifblue’ rabbiteye blueberry plants were transplanted into 4.4 kg of 1:1 v/v loamy sand:peat mixture in an 8‐liter container. Preplant P was incorporated into the mixture at 0, 20, 40, 60, and 80 kg/ha rates. Nitrogen was split‐applied post‐plant four times at 60‐day intervals beginning 30 days after blueberry bushes were transplanted. Total N rates were equivalent to 0, 112, 224, or 336 kg/ha. Plants were harvested 270 days after transplanting. Phosphorus at the 60 and 80 kg/ha rates increased plant growth 40 and 31%, respectively. Plant growth responded linearly to increasing N rate. Leaf and stem weight increases contributed to this linear response while root weight was not affected by fertilizer N. Total plant dry weight was increased by N rates at the 60 and 80 kg/ha P levels. Phosphorus applications increased leaf P levels, but did not increase soil test P. Leaf redness, caused by cool temperatures, was reduced by high N rates. The optimum P rate for fertilization of the soilrpeat mixture in the planting hole under conditions of this experiment was the equivalent of 60 kg/ha.     

Dryland corn response to tillage and nitrogen fertilization. II. P,K, CA,MG

Abstract

Nitrogen fertilization and tillage practices may influence the availability and uptake of essential plant nutrients other than N. This study was conducted to assess the interactive effects of N rate and timing and tillage practices on uptake and concentration of P, K, Ca and Mg in corn grown under dryland conditions. Potassium accumulations in no till (NT) soils were greater than in conventional till (CT) near the surface and lower than CT in the subsoil. Phosphorus and Ca levels decreased with soil depth, while Mg tended to accumulate in the subsoil. Phosphorus uptake and concentration of 5‐leaf stage corn was increased as tillage intensity decreased. Nitrogen rate at planting increased 5‐leaf P uptake but reduced P concentration; however, by silking no effect of tillage or N fertilization practice on ear leaf P concentration was obtained. Increases in 5‐leaf corn K uptake and concentration as tillage intensity decreased may have reduced Mg and Ca concentrations via cation antagonism. Ear leaf Mg and Ca concentrations were increased by N rate, probably as a result of solubilization of Ca and Mg and improved crop growth. Distribution of essential elements in the soil due to tillage in combination with varying N fertilization practices can influence temporal nutrient uptake, thereby altering plant nutrient diagnosis.     

小麦平衡配套施肥中氮素运筹

在小麦平衡配套施肥条件下研究了不同氮素运筹对氮肥的实际利用率及小麦产量的影响.结果表明:在试验条件下,氮肥以60%作基肥,20%作壮蘖肥,20%作拔节孕穗肥施用时肥料效益最高,小麦全生育期技术合理施氮量为210～240kg/hm2纯氮,施氮量在240kg/hm2纯氮时小麦产量最高.     

日光温室滴灌条件下黄瓜氮、磷、有机肥肥效与施肥模式研究

采用N、P、有机肥三因素五水平最优设计,在陕北黄土高原进行了日光温室黄瓜N、P和有机肥肥效与施肥模式的田间试验。得到了日光温室黄瓜N、P和有机肥的肥效反应模式,以及N、P和有机肥单因素对日光温室黄瓜产量的影响。结果表明N、P、有机肥对日光温室黄瓜产量增加的影响是有机肥 N P,施用有机肥是日光温室黄瓜增产的主要措施。当施P2O5量小于750 kg/km2、施氮量小于1150 kg/hm2时,N、P肥有增产效果,用量大于此施肥量时N、P肥效降低。根据反应模式提出在黄瓜目标产量在83000~88000 kg/hm2之间,95%置信区间的N、P、有机肥最佳施肥用量为N 807.5～1309.3、P2O5 576.6～991.6 kg/hm2;有机肥41.3～148.9 t/hm2。N∶P2O5为1∶0.714～0.757。日光温室黄瓜种植应以有机肥为主,氮磷肥配合施用。     

Alfalfa/grass response to nitrogen and phosphorus applications

Abstract

Alfalfa/grass (Medicago sativa/Dactylis glomerata, Bromus) yield and quality responses to nitrogen (N) and phosphorus (P) fertilizer applications are well documented. The magnitude of the P response and in turn N, may however, be limited by the relative immobility of P in the soil. A two‐year field study was conducted to determine the response of an established alfalfa/grass stand to combinations of a one‐time broadcast application of N, P, and sulfur (S) rates with fall or spring applications of P. Nitrogen and P applications increased forage production, nutrient concentration and nutrient content, particularly in the first production year. No S response was observed. Fall P applications were superior to spring applications only in the first year of production. If annual broadcast applications of P are made to existing alfalfa/grass stands in Intermountain areas, fall applications are recommended.