Water and nitrogen footprint assessment of integrated agronomic practice management in a summer maize cropping system

The footprints of water and nitrogen(WF and NF)provide a comprehensive overview of the type and quantity of water consumption and reactive nitrogen(Nr)loss in crop production.In this study,a field experiment over two years(2019 and 2020)compared three integrated agronomic practice management(IAPM)systems:An improved management system(T2),a high-yield production system(T3),and an integrated soil-crop management system(ISCM)using a local smallholder farmer’s practice system(T1)as control,to investigate the responses of WF,Nr losses,water use efficiency(WUE),and nitrogen use efficiency(NUE)to IAPM.The results showed that IAPM optimized water distribution and promoted water use by summer maize.The evapotranspiration over the whole maize growth period of IAPM increased,but yield increased more,leading to a significant increase in WUE.The WUE of the T2,T3,and ISCM treatments was significantly greater than in the T1 treatment,in 2019 and 2020respectively,by 19.8-21.5,31.8-40.6,and 34.4-44.6%.The lowest WF was found in the ISCM treatment,which was 31.0%lower than that of the T1 treatment.In addition,the ISCM treatment optimized soil total nitrogen(TN)distribution and significantly increased TN in the cultivated layer.Excessive nitrogen fertilizer was applied in treatment T3,producing the highest maize yield,and resulting in the highest Nr losses.In contrast,the ISCM treatment used a reduced nitrogen fertilizer rate,sacrificing grain yield partly,which reduced Nr losses and eventually led to a significant increase in nitrogen use efficiency and nitrogen recovery.The Nr level in the ISCM treatment was34.8%lower than in the T1 treatment while NUE was significantly higher than in the T1 treatment by 56.8-63.1%in2019 and 2020,respectively.Considering yield,WUE,NUE,WF,and NF together,ISCM should be used as a more sustainable and clean system for sustainable production of summer maize.

Nutrient Limiting Factor and Agronomic Efficiency of Wheat in Fluvo-aquic Soil District in Northwest of Shandong Province

[Objective] This study aimed to provide basis for rational fertilizer application of wheat in fluvo-aquic soil in the northwest of Shandong Province.[Method] In this paper,the treatments of reduced N,P and K were set in order to explore the effects of fertilizer recommendation based on ASI systematic approach on wheat yield,agronomic efficiency and recovery rate of nutrients.[Result] Nitrogen was the main limiting factor for wheat production in that area,followed by phosphorus,and the third was potassium.Compared with the optimum treatment （OPT）,the reduction of N,P and K reduced the grain yield obviously,which came up to 22.4％,14.4％ and 13.4％ respectively.There were no obvious differences in grain yield among Farmer＇s Fertilization Practice （FP）,60％ OPT-N and OPT treatment.[Conclusion] Agronomic efficiency of N,P and K was 6.3,12.9 and 10 kg/kg respectively.The recovery rates of N,P and K in wheat season were 16.41％,17.27％ and 27.27％ respectively.

Integrated agronomic practice increases maize grain yield and nitrogen use efficiency under various soil fertility conditions

Crop yield potential can be increased through the use of appropriate agronomic practices. Integrated agronomic practice (IAP) is an effective way to increase maize (Zea mays L.) grain yield and nitrogen use efficiency (NUE);however, the physiological processes associated with gains in yield potential obtained from IAP, particularly the different under various soil fertility conditions, remain poorly understood. An IAP strategy including optimal planting density, split fertilizer application, and subsoiling tillage was evaluated over two growing seasons to determine whether the effects of IAP on maize yield and NUE differ under different levels of soil fertility. Compared to farmers' practices (FP), IAP increased maize grain yield in 2013 and 2014 by 25% and 28%, respectively, in low soil fertility (LSF) fields and by 36% and 37%, respectively, in high soil fertility (HSF) fields. The large yield gap was attributed mainly to greater dry matter (DM) and N accumulation with IAP than with FP owing to increased leaf area index (LAI) and DM accumulation rate, which were promoted by greater soil mineral N content (Nmin) and root length. Post-silking DM and N accumulation were also greater with IAP than with FP under HSF conditions, accounting for 60% and 43%, respectively, of total biomass and N accumulation;however, no significant differences were found for post-silking DM and N accumulation between IAP and FP under LSF conditions. Thus, the increase in grain yield with IAP was greater under HSF than under LSF. Because of greater grain yield and N uptake, IAP significantly increased N partial factor productivity, agronomic N efficiency, N recovery efficiency, and physiological efficiency of applied N compared to FP, particularly in the HSF fields. These results indicate that considerable further increases in yield and NUE can be obtained by increasing effective soil N content and maize root length to promote post-silking N and DM accumulation in maize planted at high plant density, especially in fields with low soil fertility.

Effects of Non-flooded Cultivation with Straw Mulching on Rice Agronomic Traits and Water Use Efficiency

A field experiment was conducted to study water use efficiency and agronomic traits in rice cultivated in flooded soil and non-flooded soils with and without straw mulching. The total amount of water used by rice under flooded cultivation （FC） was 2.42 and 3.31 times as much as that by rice under the non-flooded cultivation with and without straw mulching, respectively. The average water seepage was 13 560 m^3/ha under the flooded cultivation, 4 750 m^3/ha under the non-flooded cultivation without straw mulching （ZM） and 4 680 m^3/ha under non-flooded cultivation with straw mulching （SM）. The evapotranspiration in the SM treatment was only 38.2% and 63.6% of the FC treatment and ZM treatment, respectively. Compared with the ZM treatment, straw mulching significantly increased leaf area per plant, main root length, gross root length and root dry weight per plant of rice. The highest grain yield under the SM treatment （6 747 kg/ha） was close to the rice cultivated in flooded soil （6 811.5 kg / ha）. However, the yield under the ZM treatment （4 716 kg/ha） was much lower than that under the FS treatment and SM treatment. The order of water use efficiency and irrigation water use efficiency were both as follows： SM〉 ZM〉 FC.

Genome-Wide Association Study of Nitrogen Use Efficiency and Agronomic Traits in Upland Rice

Genome-wide association study(GWAS)was performed for 16 agronomic traits including nitrogen use efficiency(NUE)and yield-related components using a panel of 190 mainly japonica rice varieties and a set of 38390 single nucleotide polymorphism(SNP)markers.This panel was evaluated under rainfed upland conditions in Madagascar in two consecutive cropping seasons with two contrasted nitrogen input levels.Using another set of five grain traits,we identified previously known genes(GW5,GS3,Awn1 and Glabrous1),thus validating the pertinence and accuracy of our datasets for GWAS.A total of 369 significant associations were detected between SNPs and agronomic traits,gathered into 46 distinct haplotype groups and 28 isolated markers.Few association signals were identified for the complex quantitative trait NUE,however,larger number of quantitative trait loci(QTLs)were detected for its component traits,with 10 and 2 association signals for nitrogen utilization efficiency and nitrogen uptake efficiency,respectively.Several detected association signals co-localized with genes involved in nitrogen transport or nitrogen remobilization within 100 kb.The present study thus confirmed the potential of GWAS to identify candidate genes and new loci associated with agronomic traits.However,because of the quantitative and complex nature of NUE-related traits,GWAS might have not captured a large number of QTLs with limited effects.

Nitrogen recovery and agronomic efficiency of forages with nitrogen fertilization under flooded condition

The cow-calf (Bos taurus) industry in subtropical United States and other parts of the world that depends almost totally on grazed pastures is facing several production constraints like changing climatic conditions and increasing cost of fertilizers, especially nitrogen (N). Particularly little is known about the response of forage species to the combined effect of water-logging and the addition of N. A two-year greenhouse study was conducted in 2008 and 2009 to determine i) the effect of flooding duration on N recovery and agronomic efficiency of bahiagrass (Paspalum notatum Fluegge) compared with two flooding tolerant forages, limpograss (Hemarthria altissima Poir), and maidencane (Panicum hematomon Schult) and ii) if N fertilization could mitigate the negative effect of flooding. Nitrogen recovery and agronomic efficiency varied significantly (P ≤ 0.001) among forage species. Averaged across levels of N, N recovery of bahiagrass and limpograss was reduced by about 41% and 56%, respectively after 84 d of continued flooding while N recovery of maidencane was slightly increase by about 5% between 0 and 84 d of flooding. Agronomic efficiencies of bahiagrass (41% to 26%) and limpograss (44% to 31%) were reduced by flooding while agronomic efficiency of maidencane was increased from 24% (no flooding) to 46% at 84 d of continued flooding. However, N recovery and agronomic efficiency of three forage species was positively affected by N fertilization. The overall N recovery of bahiagrass, limpograss, and maidencane ranged from 44% to 59%. Nitrogen fertilization could improve N recovery and agronomic efficiency of forage species under waterlogged condition.

Experimental Study to Improve the Agronomic Efficiency of Low Grade Fine Size Rock Phosphate

Soluble phosphate fertilizers have been preferably used in plant crop production. The cost of applying conventional water soluble phosphate fertilizer is high in developing countries since their manufacturing requires importing high grade rock phosphate （RP）. As a result, the use of indigenously available low-grade RP is gaining importance globally. In this study, experiments were carried out using clayey loamy alkaline soil to evaluate the agronomic efficiency of fine sized low grade RP with inorganic nitrogen fertilizers and it was further compared with that of soluble phosphate fertilizer （di-ammonium phosphate）, Cicer arietinum was the test crops subjected to treatments of absolute control, di-ammonium phosphate and low grade RP with varying concentrations of ammonium sulphate or ammonium nitrate. The experiments were conducted during 2012-2013 in the bid to study the growth rate and the biomass of the crop. Tests were also performed to determine the residual effects of the fertilizers on the crops. The results revealed that the combined use of low grade RP and ammonium sulphate or ammonium nitrate, at 16 kg N/ha, resulted in an agronomic efficiency, in terms of biomass of plants, comparable to that of di-ammonium phosphate and was found to be a more attractive management option for resource-poor farmers.

Coffee Orchard Response to Enhanced Efficiency Phosphate Fertilizer

Phosphorus (P) plays a crucial role in plant growth by aiding in the development of strong roots, promoting flower and fruit formation, and aiding in photosynthesis. Studies to improve P fertilizers efficiency in coffee orchards are necessary due to the need for better efficiency and the lack of information on enhanced efficiency P fertilizers. This study aimed to investigate the effect of MAP coated with anionic polymers (Policote) on coffee orchard development. A coffee trial was carried out in a randomized block design with three replications. The treatments, applied at coffee planting, were arranged in an incomplete factorial (2 × 4) + 1, using two P sources (MAP and Policote coated MAP), four P rates (40, 80, 120, and 160 g P2O5 plant-1) and control (without application of P fertilizer). Plant height was evaluated in the 2016/2017, 2017/2018, and 2018/2019 seasons, while coffee bean maturation, yield, and agronomic P efficiency use were evaluated in the last two seasons. P fertilization did not affect coffee bean maturation and increased coffee yield in 31-month-old plants when differences among P sources and rates were observed. Using Policote-coated P fertilizer resulted in higher yields at the same P rate, as well as similar yields at a lower P rate, compared to conventional fertilizer. Policote-coated P fertilizer can be used as an enhanced efficiency fertilizer and is an efficient way to deliver required P to plants. The target for reducing farm investment, increasing agricultural profits, preserving phosphatic rock reserves, and avoiding the overuse of phosphate fertilizer could be realized through the rational use of enhanced efficiency fertilizers.

推荐施肥量下控释肥替代普通尿素提高高粱产量和氮肥生产力

【目的】高粱生产中氮肥施用不合理,氮肥利用效率低,研究适宜重庆地区高粱种植的控释氮肥减施比例,在减少氮肥用量的同时,确保高粱稳产高产,提高肥料利用效率。【方法】田间定位试验于2021、2022年在重庆永川进行,供试高粱品种为晋渝糯3号和金糯粱1号。设置6个处理,分别为不施氮肥(CK);习惯尿素施肥量(U,N 180 kg/hm^(2));尿素推荐施用量(U1,减N 20%,N 144 kg/hm^(2));控释氮肥减施氮量20%(C1,N144 kg/hm^(2));控释氮肥减施氮量30%(C2,N 126 kg/hm^(2));控释氮肥减施氮量40%(C3,N 108 kg/hm^(2))。在高粱开花期和成熟期,调查干物质积累量和转运量,成熟期调查植株和籽粒氮素含量、生物量、产量及产量构成因素。【结果】开花期和成熟期高粱干物质积累量均以C1和U1处理最高,C1处理成熟期干物质积累量又显著高于U1。C1处理叶片花前干物质转运量显著高于U。花后干物质积累量C1处理显著高于其他处理,U1和C2处理显著高于U处理。C1处理晋渝糯3号和金糯粱1号花后干物质积累量对籽粒的贡献率较U分别显著提高了11.54%和12.41%。C1处理的高粱产量最高(晋渝糯3号6611 kg/hm^(2),金糯粱1号5690 kg/hm^(2)),较其他施氮处理显著提高了5.40%~18.66%;其次为C2和U1处理,二者的产量均显著高于U和C3处理。各施氮处理的氮肥生理利用率(NPE)差异不显著;减氮处理间氮肥农学利用率(NAE)无显著差异,氮肥偏生产力(NPFP)差异显著,其NAE和NPFP均显著高于习惯施氮处理U;控释肥各减氮处理的NPFP显著高于普通氮肥推荐量处理U1。C1处理较U处理大幅提高了NAE、NPFP和氮肥利用率(NUE),晋渝糯3号分别提高了58.54%、39.61%和59.28%,金糯粱1号分别提高了80.97%、48.30%和63.08%;与U1处理相比,晋渝糯3号的NPFP、NUE分别提高了5.38%和22.19%,金糯粱1号分别提高了5.82%和4.42%。【结论】推荐施氮量下,用控释肥替代普通氮肥增加了高粱开花期和成熟期干物质积累量,提高了叶片花前干物质转运量和花后干物质积累量及其对籽粒的贡献率,提升了高粱产量和氮肥利用效率,可作为西南地区高粱生产的推荐氮肥施用方式。

氮水平对苦荞生长发育及氮素吸收利用的影响

为提高西北干旱地区的苦荞产量、减少氮肥施用及提高氮肥利用效率,以适宜西北地区种植的川荞2号(CQ2)和晋荞2号(JQ2)为材料,设置4个施氮水平(0、60、120和180 kg·hm^(-2)),研究氮对苦荞生长、产量及氮素利用的影响。结果表明,随施氮量的增加,苦荞氮肥偏生产力和农学利用效率显著降低,SPAD值、干物质积累量、氮素积累量和每吨籽粒氮需要量逐步增加,而农艺指标、产量及其构成、氮肥表观利用率和氮收获指数均呈先升后降趋势,均以120 kg·hm^(-2)施氮量最高。60、120和180 kg·hm^(-2)施氮量处理下,JQ2的株粒数、有效株数和产量较CQ2平均增加6.2%、6.1%和18.2%,且其氮素吸收利用和收获指数更高,表现出更强的增产性和氮素利用能力。相关性和聚类分析发现,施氮对苦荞各指标的影响可被明显区分,苦荞的氮肥农学利用效率、氮肥偏生产力和氮收获指数与苦荞产量及构成呈极显著正相关。综合考虑氮素吸收利用效率及成本与产量因素,西北干旱地区苦荞氮施用量以120 kg·hm^(-2)为宜,品种以JQ2较为适宜。本研究结果对苦荞的高效生产及生态环境的保护具有重要的理论与实际意义。

高粱杂交种氮高效利用综合评价

为从华北、东北高粱主产区筛选出适应当地生态条件、氮利用效率更高的优质高产高粱品种,以20份国内主推高粱品种为试验材料,采用裂区试验设计,研究供试品种在不同地点的氮肥农学效率和氮肥偏生产力表现。本研究旨在筛选出适宜当地生产的氮高效高粱品种。研究结果表明:基于粱氮素农学利用率和偏生产力,将20个高粱品种分为氮高效型、氮中效型和氮低效型3类,与氮中效型和低效型品种相比,氮高效型品种具有较高的产量。聚类分析表明,在东阳地区试验中,‘晋杂34’、‘辽糯11’、‘吉杂124’、‘晋早5564’和‘金糯粮5’在2年均为氮高效型品种,其中以‘晋杂34’表现最好。在哈尔滨地区试验中,‘龙杂22’、‘龙杂25’、‘沈杂5号’、‘冀酿3号’、‘凤杂4’、‘吉杂124’、‘吉杂127’、‘辽杂37’、‘晋早5564’、‘通杂108’和‘赤杂107’在2年均为氮高效型品种,其中以‘龙杂25’表现最好。因此,东阳地区较为适宜种植的氮高效品种为‘晋杂34’,哈尔滨地区较为适宜种植的氮高效品种为‘龙杂25’。

不同带宽与行距配置对垄作冬小麦农艺性状、品质及水分利用的影响

为筛选出适宜强筋冬小麦高效的垄作栽培模式,在大田试验条件下,研究常规条播(TCK)、垄作2条带宽幅播种(T2)、垄作常规条播的3条带(T3)及垄作常规条播4条带(T4)不同结构配置处理方式对冬小麦群体分蘖、茎秆特性、光合特性、品质和水分利用效率等方面的影响。结果表明:在冬小麦整个生育时期T4处理下的分蘖数量显著低于其他处理,成熟期时T2处理的冬小麦群体数量显著高于其他处理。4种处理下的叶面积指数随着生育进程的推进呈先升高后降低的单峰曲线波动,在孕穗期出现峰值。在花后7,14,21d,以及TCK处理下的光合作用参数显著低于T2、T3处理,但显著高于T4处理。垄作栽培有助于降低冬小麦株高、重心高度、节间长度,均显著低于TCK处理。随着垄台上冬小麦行距的减少,冬小麦的株高、重心高度、节间长度逐渐升高,三者均表现为T2<T3<T4。T2与TCK、T3、T4处理相比较,其籽粒产量分别提高3.0%、1.5%和14.0%,水分利用效率分别提4.2%、0.6%和10.1%。综上所述,T2是有利于强筋小麦稳产保质节水抗倒的较优栽培方式。

Differentiation of Barley Genotypes with High Phosphorus Efficiency under Low Phosphorus Stress

[Objective] This study aimed to investigate differences in phosphorus effi-ciency between two-rowed barley and multiple-rowed barley and differences in phos-phorus efficiency among various agronomic traits, and to explore the relationship be-tween agronomic traits and row type with phosphorus efficiency. [Method] Under available phosphorus mass fractions of 1.32 and 36.6 mg/kg, 172 barley varieties, including 79 two-rowed foreign barley, 22 multiple-rowed foreign barley, 58 two-rowed Chinese barley and 13 multiple-rowed Chinese barley, were selected to com-pare differences in phosphorus efficiency-related agronomic traits. Plant height, spike length, number of unfil ed grains, number of unfil ed grains, main panicle weight, to-tal panicle weight, total stem weight, weight of aerial part and heading stage were surveyed for statistical analysis. [Result] The results showed that, various agronomic traits were larger under fertilization condition than under non-fertilization condition ex-cept number of unfil ed grains and heading stage. Plant high, spike length, weight of aerial part and heading stage varied greatly under non-fertilization condition; number of fil ed grains, number of unfil ed grains and total stem weight varied greatly under fertilization condition. In two-rowed barley, plant height and number of fil ed grains of Chinese varieties were higher than those of foreign varieties, while other agronomic traits such as spike length, number of unfil ed grains, main panicle weight, total panicle weight, total stem weight, weight of aerial part and heading stage of foreign varieties were higher than those of Chinese varieties. Spike length and weight of aerial part in multiple-rowed and two-rowed foreign barley were higher than those in Chinese barley. In multiple-rowed barley, plant height, number of unfil ed grains, total panicle weight and total stem weight of foreign varieties were higher under non-fer-tilization condition and lower under fertilization condition compared with those of Chi-nese varieties; number of fil ed grains, main panicle weight and heading stage of foreign varieties were lower under non-fertilization condition and higher under fertil-ization condition compared with those of Chinese varieties. [Conclusion] Heading stage, number of fil ed grains, number of unfil ed grains and total stem weight are more sensitive to phosphorus efficiency. Multiple-rowed barley is more sensitive to phosphorus efficiency than two-rowed barley.

氮素水平对雪茄烟苗期干物质积累及氮素营养的影响

【目的】探明氮营养水平对雪茄烟幼苗生长及氮素吸收利用的影响,为提升雪茄烟产质量提供依据。【方法】以2个雪茄烟品种(云雪38、云雪39)为供试材料,采用营养液培养法,比较缺氮(N_(0))、正常供氮(210 mg/L,N_(1))、超量供氮(420 mg/L,N_(2))对雪茄烟幼苗生长状况、干物质积累及氮素吸收利用的影响。【结果】缺氮和超量供氮烟苗均表现出典型症状,正常供氮处理在生长指标及长势长相方面均明显优于其他处理;正常供氮干物质积累量均不同程度高于缺氮和超量供氮处理,且云雪39干物质积累速率整体上均高于云雪38;超量供氮烟苗总氮积累量高于其他处理,且云雪39总氮积累量整体高于云雪38;正常供氮处理烟苗氮利用效率均显著高于超量供氮处理,且云雪39较云雪38对施氮量的响应更敏感。【结论】缺氮和超量供氮条件下,烟苗干物质积累及氮积累均受到不同程度抑制,正常供氮水平(210 mg/L)有效促进烟苗生长发育、干物质积累及氮素利用效率,不同雪茄烟品种对氮素供应水平的响应存在差异。

干旱灌区减量灌水下玉米农艺性状、产量及水肥利用效率对间作绿肥的响应

于2020—2022年采用裂区试验设计,主区设玉米‖箭筈豌豆(M‖V)和单作玉米(SM)2个种植模式,裂区设高量(I3,400 mm)、中量(I2,340 mm)、低量(I1,280 mm)3个灌水水平,探究间作绿肥对减量灌水下玉米农艺性状、产量、土壤全氮含量、水分利用效率(WUE)及氮肥偏生产力(PFPF)的影响。结果表明,与SM相比,M‖V玉米株高、茎粗、穗位高分别增加6.3%~14.3%、5.4%~12.0%和12.5%~22.1%,玉米穗长、穗粗、穗行数、行粒数分别增加5.7%~20.2%、3.7%~13.6%、2.7%~5.9%和6.8%~17.7%;间作模式下,M‖VI2与M‖VI3处理间玉米株高、茎粗、穗位高、穗长、穗粗、穗行数、行粒数差异不显著,各指标分别较M‖VI1处理显著增加6.7%~7.7%、4.9%~5.8%、7.7%~11.6%、6.2%~11.3%、2.0%~5.1%、1.0%~2.0%和5.2%~10.3%。M‖V较SM玉米增产效果显著,籽粒产量和生物产量分别提高7.7%~27.9%和5.7%~19.2%;间作模式下,M‖VI2与M‖VI3处理间玉米籽粒产量及生物产量无显著差异,两指标分别较M‖VI1处理显著增加5.7%~15.5%和4.7%~8.0%。M‖V较SM显著增加了0~40 cm土层土壤全氮含量、WUE和PFPF,增幅分别为5.8%~7.9%、12.4%~28.3%和7.7%~27.9%;间作模式下,M‖VI2与M‖VI3处理间PFPF无显著差异,较低灌水处理显著增加5.7%~15.5%,M‖VI2较M‖VI3处理WUE显著增加7.7%~10.8%。相关分析表明,间作箭筈豌豆可通过提升土壤全氮含量改善玉米株高、茎粗、穗位高、穗长、穗粗及穗行数,通过增加穗粒数和千粒重保障中量灌水(340 mm)条件下玉米产量不降低,从而提高水肥利用效率。因此,间作箭筈豌豆结合灌水340 mm可作为河西灌区水资源承载安全范围内的玉米间作绿肥高效生产模式。

施用有机肥和秸秆还田对旱地玉-麦二熟体系作物产量、品质和化肥效率的影响

为探明施用商品有机肥和秸秆还田对旱地夏玉米-冬小麦二熟体系作物产量、品质和肥料利用效率的影响,于2015—2020年度设置不施肥+秸秆不还田(CK)、施氮磷肥+秸秆不还田(NP)、施氮磷肥+秸秆不还田+商品有机肥(NPO)和施氮磷肥+秸秆还田(NPS)4个处理进行田间试验,测定并分析作物产量、氮磷肥农学效率、籽粒养分含量、蛋白质含量以及冬小麦籽粒中蛋白质组分含量。结果表明:(1)与NP和NPO处理相比,NPS处理夏玉米5 a平均产量分别显著提高21.33%和20.77%,周年产量分别显著提高9.99%和13.43%,但3个施肥处理间小麦产量差异不显著。(2)施用商品有机肥和秸秆还田对夏玉米、冬小麦的籽粒品质均有显著影响。与NP处理相比,NPO处理冬小麦籽粒各蛋白质组分含量提高5.69%~8.28%;NPS处理冬小麦籽粒氮含量、钾含量和各蛋白质组分含量分别提高4.68%、3.96%和7.75%~11.38%。相较于NPO处理,NPS处理冬小麦籽粒钾含量、谷蛋白含量、贮藏蛋白含量和谷醇比分别显著提高14.41%、9.86%、5.39%和9.65%,夏玉米籽粒蛋白质含量、产量和籽粒氮、籽粒磷含量以及周年蛋白质产量分别显著提高6.45%、28.89%、6.40%、23.08%和10.43%。(3)相较于NP和NPO处理,NPS处理夏玉米氮肥的农学效率分别提高118.35%和113.25%,周年氮、磷肥农学效率分别提高42.83%和64.36%、42.86%和64.27%,但3个施肥处理间冬小麦氮肥、磷肥农学效率5 a均值无显著差异。综合来看,长期施用商品有机肥和秸秆还田可改善冬小麦籽粒中的蛋白质组分特性,秸秆还田还能增加夏玉米籽粒钾含量和冬小麦籽粒蛋白质含量和蛋白质产量,秸秆还田较施用商品有机肥更利于提高旱地玉-麦二熟区作物产量、品质和肥料利用效率。综上所述,施氮磷肥+秸秆还田的管理模式更适宜在旱地玉-麦二熟区进行推广。

Effects of Gel-based Controlled Release Fertilizers on Agronomic Characteristics and Physiological Indices of Corn

[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers （CRFs） on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer （CF）. [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time （CF1）, and 19.6% and 15.4% with CF application at two times （CF2）, respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.

沼液不同施用量对水芹生长发育与田面水氮素排放的影响

【目的】探明沼液不同施用量对水芹生长发育与田面水氮素排放的影响,筛选适宜的沼液量与化肥配比,为化肥减量和沼液的资源化利用提供参考。【方法】以宜兴实心芹为研究对象,采用盆栽试验,研究不施肥(CK)、常规施肥(N_(0))、沼液50%替代化肥(N_(50))和沼液100%替代化肥(N_(100))对水芹生长发育、田面水总氮和铵态氮浓度及氮素利用率的影响。【结果】不同施肥处理水芹的生长状况、营养品质、田面水的总氮和铵态氮浓度及氮素利用率不同。沼液50%替代化肥处理可显著提高水芹茎鲜重、叶鲜重、地上部鲜重和株高,分别为46.68 g/Pot、16.20 g/Pot、64.23 g/Pot和49.53 cm;增加茎部和叶部的总叶绿素、类胡萝卜素、维生素C含量,分别为0.21 mg/g FW、0.03 mg/g FW、2.61 mg/100g FW和2.02 mg/g FW、0.31 mg/g FW、28.08 mg/100g FW;硝酸盐含量较常规施肥处理分别显著降低30.52%和48.77%;同时降低了水芹田面水总氮和铵态氮浓度,经2次追肥后分别在11 d和23 d达峰值,为113.14 mg/L和38.49 mg/L;氮肥偏生产力和农学效率均达最大,分别为53.53 kg/kg和12.37 kg/kg。【结论】采用沼液50%替代化肥施用有利于促进水芹生长,提高营养品质,同时降低由降雨等引发的氮素排放风险,可在水芹种植上推广应用。

陇中旱农区不同品种马铃薯水氮利用效率研究

以12个马铃薯品种为研究对象,连续2 a(2022—2023年)设置不施氮(0 kg·hm^(-2))和施氮(180 kg·hm^(-2))2个施氮水平,分析不同品种马铃薯产量和水氮效率特征,并采用隶属函数法对各马铃薯品种进行综合评价。结果表明:品种、氮水平和品种×氮水平都对晚熟马铃薯产量均具有极显著影响,而氮水平×品种对中熟品种无显著影响。连续2 a供氮条件下中熟品种产量变幅为8289.39~22011.61 kg·hm^(-2),晚熟品种产量变幅为8192.57~20308.58 kg·hm^(-2)。基于2 a施氮和不施氮条件下各品种块茎产量,将不同马铃薯品种按照不同氮效率划分为4种类型,即双高型(‘京张薯1号’、‘陇薯20号’、‘青薯9号’、‘陇薯15号’、‘陇薯16号’)、低氮高效型(‘V7’、‘陇薯14号’)、高氮高效型(‘陇薯10号’)和双低型(‘冀张薯12号’、‘希森6号’、‘定薯3号’、‘陇薯22号’)。相关性分析结果表明:氮素吸收效率、氮肥表观利用率与产量呈极显著正相关关系(R^(2)=0.4438**,R^(2)=0.4211**),马铃薯产量与块茎含氮量间呈极显著正相关关系(R^(2)=0.5302**,R^(2)=0.4357**),说明在施氮和不施氮条件下,马铃薯块茎含氮量越高则其产量越高。隶属函数分析结果表明:中熟品种‘京张薯1号’(D i=0.90)、晚熟品种‘青薯9号’(D i=0.90)和‘陇薯10号’(D i=0.87)具有较高的综合水氮效率和产量表现,可作为水氮高效品种在陇中旱作区进行推广。

合理增施有机肥减施化肥对新沂水蜜桃生产的影响

为筛选出适宜新沂地区水蜜桃的最佳有机肥替代化肥比例,研究商品有机肥45 t/hm^(2)施用量下分别减施10%、20%、30%和40%化肥的应用效果,并对水蜜桃的产量和品质进行测定,分析有机肥替代的经济效益和肥料农学效率。结果表明,增施有机肥并减施10%和20%化肥虽然成本较增施有机肥并减施30%和40%高,但产量增加较多,经济效益有所增加,总体经济效益和肥料农学效率提高。有机肥替代化肥均可改善果实品质,可潜在提高经济效益。有机肥替代化肥处理均增加了肥料农学效率,增施有机肥并减施10%和20%化肥对肥料利用效率最佳。