Application Effect of Water-absorbent Slow Release Nitrogen Fertilizer in Latosol

[Objective] A new-type water-absorbent slow release nitrogen fertilizer（WASRNF） was produced through polymerization reaction. Its physicochemical property and application effect in latosol were studied. Feasibility of using WASRNF to improve the serious problems of latosol in rubber planting area in Hainan Island including vulnerable nutrient, free-running fertilizer and water was studied. [Result] The results showed that raw materials of WASRNF, urea and water-retention material formed co-polymer through hydrogen-bond interaction that the WASRNF contained many hydrophilic groups. The p H value of WASRNF is near neutral and its water absorbent rate in tap water could reach 167.17 g·g-1. The water absorbent rates in latosol leach liquors with water/soil ratios of 1：5, 1：10 and 1：20 were 104.66, 122.93 and 145.38 g·g^-1, respectively. The maximum water holding ratio of latosol increased by 23.72%, 30.89% and 39.68% when 0.5%, 1% and 2% WASRNFs were added to latosol, and water evaporation rate of latosol decreased efficiently. Compared with common urea, WASRNF could slow down the leaching rate of nitrogen and the initial leaching amount was only 22.17% of the total amount. [Conclusion]The results indicated that WASRNF in latosol had strong water absorption and water-retention abilities in addition to the good slow release effect, and could efficiently decrease nutrient loss, increase utilization ratio of water and fertilizer and promote interaction between water and fertilizer.

Characteristics and Performance of Novel Water-Absorbent Slow Release Nitrogen Fertilizers

In this article, a research on the characteristics and performance of water-absorbent slow release nitrogen fertilizer （WASRNF） using infrared spectroscopy （IR）, scanning electronic microscopy （SEM）, differential scanning calorimetry （DSC）, and thermogravimetry analysis （TGA）, was present. The results indicate that the water absorbency and nitrogen analysis of WASRNF is 103 g g^-1 and 30%, respectively, and WASRNF exhibits approximately neutral pH and very low salt index. WASRNF is a copolymer of nitrogen fertilizer and super absorbent polymer （SAP） monomers which is formed through hydrogen bond interaction, and the molecule contains hydrophilic groups, which is responsible for the absorption and water retention capacity of the molecule. WASRNF is a gel that exhibits the ability to swell, but does not dissolve in water. WASRNF shows non-homogenous nature as a whole, but in local zone it is homogenous, the copolymer molecule shows chain network that is the physical structure responsible for absorption and retention of water in WASRNF. The water retained in WASRNF exists as free and nonfreezing bound and freezing bound water states, with the free and the nonfreezing water accounting for more than 95% of water retained in WASRNF, and the nonfreezing bound water for less than 5%. WASRNF functions in delaying the release of nitrogen from it, thereby serving a novel slow release nitrogenous fertilizer.

Differences of yield and nitrogen use efficiency under different applications of slow release fertilizer in spring maize

Excessive or insufficient application of fertilizer has raised broader concerns regarding soil and environmental degradation.One-time application of slow release fertilizer (SF) has been widely used to reduce yield gap with potential maize yield and improve nitrogen use efficiency (NUE).A 2-year field experiment (2018–2019) was conducted to evaluate the effects of SF rates from 0 to 405 kg N ha^(–1) (named F0,SF225,SF270,SF315,SF360,and SF405) and 405 kg N ha^(–1) of common fertilizer(CF405) on the grain yield,biomass and N accumulation,enzymatic activities related with carbon–nitrogen metabolism,NUE and economic analysis.Results indicated that the highest grain yields,NUEs and economic returns were achieved at SF360in both varieties.The enzymatic activities related with carbon–nitrogen metabolism,pre-and post-silking accumulation of biomass and N increased with increasing SF rate,and they were the highest at SF360 and SF405.The grain yield at SF360had no significant difference with that at SF405.However,the N partial factor productivity,N agronomic efficiency and N recovery efficiency at SF360 were 9.8,6.6 and 8.9% higher than that at SF405.The results also indicated that the average grain yields,NUE and economic benefit at SF405 were 5.2,12.3 and 18.1% higher than that at CF405.In conclusion,decreasing N rate from 405 kg ha^(–1)(CF) to 360 kg ha^(–1)(SF) could effectively reduce the yield gap between realized and potential maize yields.The N decreased by 11.1%,but the yield,NUE and economic benefit increased by 3.2,22.2 and 17.5%,which created a simple,efficient and business-friendly system for spring maize production in Jiangsu Province,China.

Used for the Study of Nitrogen Fertilizer Slow-Release Carrier Life Sludge

After the sewage treatment, putting the wet sludge in which the heavy metal content is extremely low, corrupt and broken straw, bentonite, urea in proportioning according to the certain ratio, mixing well-distributed, taking the shape of Nitrogen slow-release fertilizers, doing the dynamic bioleaching test by the method of Artificial rainfall simulation, researching the slow-release characteristic, water retention. When the mass ratio of the wet sludge whose water content is 82.5%: bentonite: corrupt and broken straw: urea is 62.5: 12.5: 12.5: 12.5, drip washing the 10g Nitrogen slow-release fertilizers by the 80ml distilled water after 48h, the residue rate of urea is 29.63%; Under the room temperature of 25 ℃, 77%RH, moisture evaporate 46.32% after 60 h. The results demonstrate that the slow-release fertilizer has a good release-effect of nitrogen and water conservation effect. It provides the basic for the development and application of the sewage in the aspect of Nitrogen slow-release fertilizers.

Release Characteristics of Different N Forms in an Uncoated Slow/Controlled Release Compound Fertilizer

This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer （UCRF） and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations： the first-order kinetics equation [N1=N0 （1-e^-kt）], Elovich equation （N1=a ＋ blnt）, and parabola equation （N1=a ＋ bt^0.5）, with the best fitting by the first-order kinetics equation for different N （r= 0.9569^＊＊-0.9999^＊＊）. The release potentials （No values estimated by the first-order kinetics equation） of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^＋-N 〉 NO3^-N in water, and total N 〉 NH4^＋-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate （k values and b values） for different N forms were in decreasing order of total N 〉 DON 〉 NH4^＋-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^＋-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^＋-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 （l-e^kt）] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.

Nitrogen deposition and release pattern of slow release fertiliser made from urea-impregnated oil palm frond and rubberwood chips

The fertiliser industry faces a continuing challenge to improve the efficiency of their products,particularly of nitrogenous fertilisers,and to minimise adverse impacts.Therefore,a new slow release fertilizer,ureaimpregnated woodchips from tropical plant biomass(oil palm frond and rubberwood),was developed.The morphology of the impregnated woodchips was investigated by scanning electron microscopy and the success of impregnation of urea and nitrogen deposition into the woodchips was confirmed by energy dispersive X-ray spectrometry.When nitrogen release patterns from impregnated woodchips fertiliser were simulated using a soil solution and distilled water as leaching solutions in a static condition for 768 h,release was slow and steady,although the release rate was lower in distilled water than in the soil solution.

Effects of Nitrogen Fertilizer Level on Chlorophyll Fluorescence Characteristics in Flag Leaf of Super Hybrid Rice at Late Growth Stage

To compare the effects of slow-release nitrogen fertilizer at six different levels on the flag leaf chlorophyll fluorescence characteristics of super hybrid rice, a field fertilization experiment was conducted with super hybrid rice Y Liangyou 1 as a test material. The photosynthetic electron transport rate （ETR）, effective quantum yield （EQY）, photochemical quenching coefficient （qp）, and non-photochemical quenching coefficient （NPQ） of flag leaves were measured at the initial heading, full heading, 10 d after full heading and 20 d after full heading stages. Results showed that the values of ETR, EQY and qp increased with rice development from initial heading to 20 d after full heading, whereas the NPQ decreased. During the measured stages, ETR, EQY and qp increased initially and then decreased as nitrogen application amount increased, but they peaked at different nitrogen fertilizer levels. The maximum ETR and EQY values appeared at the treatment of 135 kg/hm2 N. In conclusion, the optimum nitrogen amount for chlorophyll fluorescence characteristics of super hybrid rice was 135-180 kg/hm2.

无机包裹缓释肥对水稻生长与氮肥利用的影响

研究地上、地下养分供需匹配、保障产量和提高氮肥利用效率的一次性施肥产品及配套施用技术,是现代化、规模化、轻简化水稻生产的迫切需求。本文探究无机包裹型缓释肥一次性施用技术,为水稻养分高效吸收和管理精准轻简的施肥策略提供理论依据。采用盆栽试验,设置4个处理:不施肥(CK)、常规分次施肥(FP)、一次性施用无机包裹型缓释肥料(DF)和减量20%一次性施用无机包裹型缓释肥料(JF),比较水稻生长发育、花前花后干物质及氮素积累转移、产量、土壤无机氮动态变化特征和氮肥利用率的差异。结果表明:一次性施无机包裹型缓释肥DF处理水稻产量达8403.57 kg/hm 2,较常规施肥FP处理增产13.02%,减量20%一次性施无机包裹型缓释肥JF处理与FP处理产量差异不显著。DF处理可在改善花前干物质转运量的同时提高花后干物质量,花后干物质量对籽粒产量的贡献率较FP处理提高16.18%。DF、JF处理促进了水稻根系的发育,分蘖期总根长达455.84~530.42 cm,较FP处理提高12.13%和30.48%。整个生育期内DF、JF处理土壤无机氮浓度(59.45~14.96 mg/kg)始终高于FP处理(55.84~12.71 mg/kg)。DF处理较FP处理氮肥农学效率显著提高23.01%、当季回收率显著提高63.80%、氮肥偏生产力显著提高13.01%。一次性基施无机包裹型缓释肥料可实现水稻增产,氮肥利用率显著提高,为水稻高产高效和轻简化栽培提供了增效肥料产品和可行性施肥策略。

Management and Reduction of Chemical Nitrogen Consumption in Agriculture

Nitrogen is an effective material for improving the crop production. There is a big concern about rising chemical nitrogen usage as fertilizer in soil, because some forms of nitrogen absorbs in soil and causes an increase of environment and water pollution and decrease fertilizer efficiency. Composted cow manure is an important resource of organic nitrogen which improves the soil conditions. However, low density of composted cow manure and inconstant nutrient content are two factors that limit the application of composted cow manure. The densification technology is an effective solution for both problems. In this research first the capability of single screw extruder for production of fertilizer pellets including composted cow manure and nitrogen fertilizer was studied and then the effect of fertilizer pellet on the reduction of chemical nitrogen consumption was evaluated. The response of basil plants was determined in three treatments: T1 control (no fertilizer), T2 (nitrogen fertilizer) and T3 (pellet). The results showed that pelletization can be used as a proper method for slow-release nitrogen fertilizer;enhance nitrogen uptake and reducing the chemical nitrogen consumption. The results also showed that all basil responses (chlorophyll content, total weight, leaves weight, root weight and leaf area) were significantly affected by application of N fertilizer and pellet. While maximum recorded parameters were observed with application pellet.

聚脲甲醛缓释肥减量深施对小麦和玉米产量及氮肥吸收率的影响

为了探究聚脲甲醛缓释肥(PF)减量深耕对小麦和玉米作物产量、氮肥利用效率以及矿质养分迁移的影响,设置对照(CK)、尿素+旋耕(OPTX)、尿素+深耕(OPTS)、PF+旋耕(PFX)和PF+深耕(PFS)5个处理,在豫南砂姜黑土小麦、玉米农田开展大区试验。结果表明,对比传统尿素(OPT)处理,PF处理小麦、玉米产量显著高于OPT处理,尤其PFS处理较OPTX处理小麦和玉米季产量分别高12%和6.4%,较OPTS处理分别高3.4%和1.8%;与产量不同,PFS处理仅显示玉米季氮肥利用率(NUE)高于OPTX和OPTS处理,而小麦季NUE甚至低于OPTS处理,这可能与PF在小麦季深耕条件下养分释放速度慢有关。对比两种耕作方式,发现PFS处理小麦季产量与PFX处理产量无显著差别,而玉米季产量显著高于PFX处理;与产量不同,PFS处理小麦季NUE显著低于PFX处理,而玉米季无显著差别,这可能与玉米季更适宜的气象条件和小麦季PF养分的后续释放有关。对比土壤铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)残留量和总氮浓度,发现作物收获后,PFS处理0~30和30~60 cm土层NH_(4)^(+)-N残留量与PFX处理无显著差异,NO_(3)^(-)-N残留量显著低于PFX处理,而总氮含量略高于PFX处理,这可能与PF处理在小麦季深耕条件下氮素未释放完全有关。总而言之,依据作物的产量和氮肥利用效率,聚脲甲醛缓释肥在深耕条件下显示出更高的产量效益和增产潜势,尤其玉米季作物吸氮量、产量和NUE有了显著提升,值得被推荐。

生物炭辅配硫酸铵对土壤氮素淋溶的影响

为探究添加生物炭对硫酸铵肥料中氮素释放性能的影响。通过土柱淋溶模拟试验研究不同炭肥比(1∶3、1∶4、1∶5)下制备的生物炭-硫酸铵肥料(BC-AS_(1/3)、BC-AS_(1/4)、BC-AS_(1/5))的氮素淋失特征。结果表明:1)添加生物炭能够有效吸附硫酸铵肥料,减缓硫酸铵的氮素释放速率。3种不同炭肥比下,BC-AS1/4处理的生物炭-硫酸铵颗粒表面最为光滑紧密,成型性最好;2)与常规硫酸铵处理AS相比,不同炭肥处理均显著改善了土壤保水保肥性能,减少了土壤无机氮淋失。其中BC-AS(1/4)处理的铵、硝态氮累积淋出量相较于AS处理分别降低80.83%、11.56%,表现出最小的淋出速率和累积淋失量,缓释效果最好;3)相较于常规硫酸铵处理AS,不同炭肥处理均提高了土柱土壤氮素累积。其中BC-AS1/4处理表现出最好的养分固持效果;4)各土层土壤有机碳含量与土壤全氮呈正相关关系,生物炭-硫酸铵肥料中碳的投入能够有效提高土壤养分的持有能力。综上,生物炭-硫酸铵肥料能够有效减缓氮素释放速率,减少氮素养分淋失,提高土壤养分持有能力,有利于提高肥料利用效率。其中炭肥比为1∶4时生物炭与硫酸铵结合效果最好,表现出最佳的缓释效果及培肥特征。

缓释掺混肥配比对稻茬小麦产量、氮素利用和籽粒品质的影响

为探究不同缓释掺混肥配比对稻茬小麦生产的影响,在沿淮下游地区,以淮麦52和淮麦920为材料,通过随机区组试验,以缓释掺混肥(SRF,N∶P2O5∶K_(2)O=26∶12∶12)和丰卉尿素(U,46%N)为供试肥料,设置U四次分施(M_(1))、SRF一次基施(M_(2))、60%SRF基施+40%U拔节期追施(M_(3))、60%SRF基施+40%SRF返青期追施(M_(4))、M_(3)模式减氮15%(M_(5))和M_(4)模式减氮15%(M_(6))6种施肥模式,分析了不同处理下小麦产量、氮素积累及利用、干物质转运和品质等的差异。结果表明,缓释掺混肥一次基施(M_(2))和减氮15%条件下两次分施(M_(5)和M_(6))较常规肥料处理(M_(1))均能实现稳产。缓释掺混肥两次分施(M_(4))可有效促进稻茬小麦花后光合物质生产和氮素向籽粒运转,增加籽粒氮素积累量,提高氮肥利用率,氮肥农学效率、氮肥表观利用率、氮素生理效率和氮收获指数分别较M_(1)处理增加16.49%、11.09%、4.86%和4.72%,较M_(2)处理增加21.31%、15.19%、5.32%和18.60%;M_(4)处理较M_(1)处理增产9.01%和6.78%,较M_(2)处理增产11.43%和12.10%,实现产量提升的同时显著改善小麦籽粒蛋白品质。综上,60%缓释掺混肥基施和40%缓释掺混肥返青期追施有助于实现小麦的高产优质高效生产,适宜在沿淮下游稻茬麦区推广应用。

腐植酸基质缓释尿素对氮素淋失和氨挥发的阻控

[目的]基质缓释型氮肥(控失尿素)降低氮素释放的功能主要通过控失剂降低肥料中尿素的释放和在土壤中的转化而实现。腐植酸含有大量功能基团,施入土壤后可减少氮素的转化。本研究尝试了用腐植酸替代部分控失剂来改善基质缓释型氮肥对氮素的固持功能。[方法]共采集了6种氮肥进行试验,包括普通尿素(urea,U)、控失剂添加比例分别为4%、6%、8%的3个基质缓释氮肥(LU1、LU2、LU3,LU-Loss-control urea),以3.5%腐植酸等量替代LU2处理中的控失剂制备的腐植酸基质缓释氮肥(humic acid/loss-control urea,HLU),以及添加了抗结剂(主要成分为纳米碳粉)的腐植酸基质缓释氮肥(humic acid/loss-control urea with antisetting agent added,HLUA)。室内淋溶试验以不添加氮肥为对照,将6个肥料样品埋入土壤后,连续15天收集淋洗液,分析全氮、硝态氮和铵态氮含量,并采用氨气检测管法测定氨挥发速率。采用傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)、核磁共振(nuclear magnetic resonance,NMR)和X射线光电子能谱分析(X-ray photoelectron spectroscopy,XPS)、热重分析(thermogravimetric analysis,TG)、比表面积吸附(Brunauer-Emmett-Teller,BET),分析了控失剂、尿素、基质缓释尿素和腐植酸基质缓释尿素的化学结构、孔隙结构以及热性质。[结果]随着控失剂(control release agent,CLA)含量的增加,基质缓释尿素对氮素的固持作用增强,淋失和氨挥发量降低。与尿素(U)相比,LU1、LU2、LU3、HLU、HLUA的全氮累积淋溶量分别降低了24.5%、32.2%、34.9%、31.5%和32.2%,累积氨挥发量分别降低了13.1%、24.3%、27.1%、28.0%和29.5%。HLU、HLUA处理的氮素淋失和氨挥发量与LU2处理没有显著差异。化学结构表征分析表明,控失剂的主要成分凹凸棒土和腐植酸都与尿素形成了强度相当的分子间氢键,纳米碳粉与尿素间无氢键形成。在腐植酸基质缓释尿素中加入少量防结剂纳米碳粉,对其分子内氢键强度、热稳定性以及氮素淋失和氨挥发特征均没有显著影响。[结论]在尿素中加入腐植酸、控失剂和防结剂制备的腐植酸基质缓释尿素,不仅加工和储存中不易粘连,具有较低的氮素淋失和氨挥发损失风险,还可作为一种兼具改良障碍土壤的多功能缓释肥料使用。

不同灌水定额下缓释氮肥与尿素混掺对玉米生长和产量及水肥利用效率的影响

为旱区建立玉米种植的高效水肥管理技术提供理论依据。通过玉米盆栽试验,设置3个灌水定额(W1:2 548 m^(3)/hm^(2),W2:1 911 m^(3)/hm^(2),W3:1 433 m^(3)/hm^(2))和3个氮肥类型(U:尿素,UNS:尿素与缓释氮肥以纯氮含量比3∶7混掺,SRF:缓释氮肥),以不施氮肥W3灌溉量为对照(CK),研究不同灌水量和氮肥类型对玉米生长指标、产量及构成、灌溉水分利用效率(IWUE)及氮素利用效率(NUE)的影响。结果表明,氮肥类型与灌溉量及两者交互作用对玉米生长指标、单株干物质累积量、产量及产量构成要素、IWUE和NUE有显著影响(P<0.05)。不同氮肥类型处理下,W1水平下的平均玉米株高、叶面积、叶绿素含量、净光合速率、单株干物质累积量、产量及产量构成和NUE均显著高于W2和W3。同一氮肥类型在不同的灌溉量下对玉米生长的响应有所差异。W1灌溉水平下,SRF的平均产量较UNS和U分别提高2.01%和12.71%,但在W2和W3灌溉水平下,产量的整体趋势表现为UNS>SRF>U。处理W3UNS的IWUE最高,处理W1UNS的NUE最高。通过整体差异组合评价模型分析得出排名前两名的处理为W1SRF和W1UNS。综合分析,灌溉量2 548 m^(3)/hm^(2)的前提下,缓释氮肥或缓释氮肥与尿素混掺一次性基施,可同时兼顾玉米生长、产量和水肥利用效率。

不同氮肥类型对稻-油轮作氨挥发和氮肥利用率的影响

水稻-油菜(稻-油)轮作是我国代表性轮作方式之一,然而不合理的氮肥施用导致稻-油轮作系统氮肥利用率下降和氮素流失。为此,本研究采用随机区组设计,以不施氮肥(CK)为对照,设尿素(UF)、缓释肥+尿素(SF)、尿素+硝化抑制剂+脲酶抑制剂(DF)和生物炭+尿素(BF)4个处理,拟探明不同氮肥类型对稻-油轮作系统氨挥发和氮肥利用率的影响。结果表明,不同氮肥类型显著影响NH_3挥发、氮肥利用率与作物产量。1)各处理水稻季氨挥发均高于油菜季。与CK相比,UF、SF、DF和BF处理周年累积NH_3挥发量分别显著提高1.6倍、1.0倍、1.1倍和0.8倍。与UF相比,SF、DF和BF周年累积NH_3挥发量分别显著降低20.5%、19.7%和30.9%。2)与UF相比,SF、DF和BF油菜季氮肥吸收利用率分别提高27.9%、10.3%和19.3%,水稻季氮肥吸收利用率分别提高49.3%、32.8%和41.5%。3)与UF相比,SF、DF和BF油菜产量分别提高6.7%、2.8%和4.3%,水稻产量分别提高36.7%、14.0%和23.4%。与UF相比,SF油菜季经济效益提高24.3%,SF、DF和BF水稻季经济效益分别提高70.7%、21.1%和1.1%,其中SF经济效益最高。本研究结果表明,缓释肥+尿素能显著减少稻-油轮作NH_3挥发损失,并更有效地提高氮肥利用率、作物产量和经济效益,是一项经济生态的施肥模式。

缓释肥类型及其运筹方式对弱筋小麦产量及品质的影响

为探究缓释肥类型及施用模式对小麦产量和品质的调控作用及机制,以弱筋小麦扬麦33为供试材料,选取3种类型(8种品牌)的缓释肥[包膜型缓释肥(S1~S5)、合成型微溶性缓释肥(S6)、化学抑制剂型缓释肥(S7、S8)]作为供试氮源,设置缓释肥一次性基施(M1)和基施60%+返青期追施40%(M2)两种施肥模式,常规尿素施肥(基肥∶壮蘖肥∶拔节肥∶孕穗肥为5∶1∶2∶2)为对照(CK),分析了相同施氮水平下缓释肥类型及其运筹方式对小麦产量、氮素积累转运、氮效率、品质和效益的影响。结果表明,与CK相比,同一品牌缓释肥在不同施肥模式下小麦产量、开花期和成熟期氮素积累、籽粒氮素积累、花前氮素转运量及转运效率、花后氮素积累及其对籽粒的贡献率和氮利用效率均表现为M2>CK>M1。其中,M2模式下小麦显著增产的缓释肥依次为S6>S1>S2>S3>S8。M1模式下各处理小麦籽粒品质指标均符合弱筋小麦国家标准;M2模式下除S2、S6外,其余缓释肥的小麦籽粒品质指标均符合弱筋品质要求。除M2S5外,其余处理产值及净效益均表现为M2>CK>M1。综合认为,本试验条件下,S1(硫包膜型)、S3(树脂包膜型)、S8(抑制型)缓释肥基施60%+返青期追施40%可实现弱筋小麦产量、品质、氮效率和经济效益的协同提升。

功能性缓释掺混肥料对玉米产量及土壤氮含量的影响

根据玉米需肥规律开发了功能性缓释掺混肥,为考察其对玉米生长及土壤氮素含量的影响,开展了田间小区试验。试验共设6个处理,以不施肥(CK1)、普通掺混肥(CK2)处理为对照,调查了玉米生物学性状、产量以及玉米收获后土壤中硝态氮、铵态氮、碱解氮含量等指标。结果表明:在等施肥量条件下,功能性缓释掺混肥处理的玉米产量比CK2处理的增产7.98%,差异显著;在功能性缓释掺混肥施用量减少20%的条件下,不会造成玉米减产;功能性缓释掺混肥处理的氮素农学利用率比CK2处理的提高7.98%~26.82%;在等施肥量条件下,功能性缓释掺混肥处理的0~20 cm土层中硝态氮和碱解氮含量比CK2处理的分别提高了10.34%和17.39%,铵态氮含量降低了14.29%。

不同缓释肥料用量及运筹方式对杂交晚稻农艺性状及产量的影响

为筛选出适合晚稻生产的肥料运筹方式,减少肥料成本、增加经济效益,以籼粳杂交晚稻甬优7850为试验材料,研究不同缓释肥料用量及运筹方式对产量、农艺性状及氮素效率的影响。结果表明,等养分处理下,有机无机缓释肥有利于提高有效穗、每穗粒数,667 m^(2)基肥使用30 kg加适量分蘖肥较常规施肥增产4.80%,氮肥农学效率最高;等成本情况下,缓释肥处理氮素减少,产量仍较常规施肥增加1.53%,且氮肥农学效率明显高于常规施肥。双季晚稻有机无机缓释肥以667 m^(2)基肥用量30 kg、总氮量在10.7~12.0 kg为宜。

自然降雨和施用缓释肥对北运河上游大田氮磷径流流失的影响

在北运河上游流域,通过大田监测试验,研究了自然降雨条件下不施肥(T_(1))、传统施肥(T_(2))、缓释肥(T_(3))3种不同施肥处理玉米生长季氮磷径流流失的影响。结果表明:当流域内12 h内降雨量超过30 mm时,土壤含量水呈饱和状态,由此地表径流液产生;若在1 h内降雨量超过30 mm,则会加剧径流的产出。与T_(2)处理相比,T_(3)处理的总氮、总磷、铵态氮、硝态氮流失量均偏低,分别低15.3%、24.2%、10%和12%,但未达到显著性差异。T_(3)处理的总氮流失率为0.07%,较T_(2)处理减少46.2%;T_(3)处理的总磷流失率为0.13%,较T_(2)处理减少71.7%;T_(3)处理的硝态氮流失率为0.06%,较T_(2)处理减少25%。综上,与传统施肥相比,施用缓释肥在减少氮磷流失方面能起到一定的减排作用,对科学推广缓释肥和评估缓释肥对氮磷流失的减排效果提供了数据支撑。

缓控释肥料对水稻产量和品质的影响

以云南省普洱市墨江哈尼族自治县通关镇为试验地点,考察缓控释肥料对水稻产量和品质的影响。结果显示,缓控释肥料的缓释期可对水稻生长形状与产量产生影响,当水稻品种为清香优2238与深两优2808时,缓释期为100天的缓释氮肥效果要优于60天缓释期。清香优2238在B2条件下的产量最高为9.61 t/hm^(2),深两优2808在B2条件下的产量最高为11.78 t/hm^(2)。60天缓释氮肥处理下的杨籼优919产量优于100天缓释氮肥,A3条件下杨籼优919产量较高为10.68 t/hm^(2)。