Short-Term Effect of Grazing Exclusion and Uncontrolled Grazing on Species Abundance, Dry Matter Yield and Nutritive Value in an Invaded Area by Euryops floribundus in the Eastern Cape, South Africa

Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m2 quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha-1) compared to UG site (1102 kg·ha-1). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.

Effects of Cutting Interval between Harvests on Dry Matter Yield and Nutritive Value in Alfalfa

Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.

Comparative Effects of Cocoa Pod Husk and Oil Palm Bunch Ash on Nutrient Uptake, Growth and Dry Matter Yield of Cocoa (The-obroma cacao) in Ibadan, Southwest Nigeria

The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7&deg25'N Long. 3&deg25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.

Influence of High Temperature Stress on Net Photosynthesis, Dry Matter Partitioning and Rice Grain Yield at Flowering and Grain Filling Stages

Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress （HTS） on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.

Effects of Site-Specific Nitrogen Management on Yield and Dry Matter Accumulation of Rice from Cold Areas of Northeastern China

The effects of yield increase and mechanism of site-specific nitrogen management （SSNM） in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer＇s fertilization practice （FFP） were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% （P 〈 0.05）, and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% （P 〈 0.05） and 39.8-194.3% （P 〈 0.05）, respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period.

Effects of Calcium Application Rate on Dry Matter Accumulation and Yield of Peanut

The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results showed that number of full fruit,dry weight per plant,kernel yield,and pod yield all increased with calcium application increased,and they decreased when calcium application rate was more than150 kg/ha. Both the height of main stem and the length of side shoot decreased with calcium application increased. Therefore,to obtain the optimal agronomic character index and the highest yield benefit,the suggested calcium application rate would be 150 kg/ha for peanut.

Soil tillage methods by years interaction for dry matter of plant yield of maize (Zea mays L.)using additive main effects and multiplicative interaction model

The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha(for no-plough tillage in 2005) to 246.4 dt ha(for complete conventional tillage in 2012), with an average of 146.6 dt ha. In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.

Temporal Stability of Sward Dry Matter and Nitrogen Yield Patterns in a Temperate Grassland

The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.

Effects of Limited Water Supply and Ridge Plotted Field on Soybean Yield and Dry Matter Accumulation

The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.

The heterotic effects on dry matter production and grain yield formation in hybrid rice

We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar

Film mulching treatment inf luences dry matter and yield of oil flax in semi-arid area of China

A field study was set up to compare dry matter accumulation and grain yield of 3 different types of film mulching, namely FFC(full film muched on tiny ridges covered with soil), PFC(full film muched covered with soil), and PF(full film muched with no cover). The experiment was laid out in a complete random design with 3 replications at northwest(34°40′N, 105°06′E) of China. This study determined that(1) film mulching treatment increased leaf area and dry matter accumulation of oil flax in semi-arid areas;(2) accumulation of dry matter under PFC treatment was markedly higher than other treatments except anthesis stage;(3) average grain yield of oil flax under film mulching treatment was 52.67%-60.33% higher than flat plot without mulched or ridge(CK) treatment;(4) grain yield of oil flax was substantially correlated with plant height, grain number and 1,000 kernels weight. This study demonstrated that film mulching has significant effects on crop grain yield improvement in the northwest of China.

Nitrogen Uptake Dynamics and Dry Matter Production of Rice in Response to Nitrogen Fertilizer Application

氮是在米饭生产的最重要的营养素之一，但是它的举起动力学仍然保持相对未经勘探。现在的调查在氮化肥申请的不同层次在成长季节评估了举起动力学。实验在孟加拉国瑞斯研究院试验性的农场在 Boro 季节(11 月 4 月) 期间被进行， Gazipur，孟加拉国。实验包含了二现代米饭 varietiesBRRI dhan28 和 BRRI dhan29 和六 N 率：0， 50， 100， 150， 200 和 250

茭虾共作对土壤氮磷含量和茭白干物质积累及氮磷钾吸收分配的影响

为探究茭白种养模式的施肥策略,设置茭虾共作(ZC)、茭白单作(Z)2个处理,研究茭虾共作对土壤氮磷含量、茭白产量和茭白干物质积累及氮磷钾吸收分配的影响。2021-2022年的研究结果显示,茭虾共作模式较茭白单作模式采茭期土壤中全氮、全磷、速效磷的含量分别提高了10.85%~38.89%、5.45%~13.79%、6.19%~61.79%,净茭产量提高了5.10%~19.54%,采茭期茭白茎、叶、净茭的干物质积累量分别增加14.41%~16.58%、10.28%~15.15%、10.57%~21.45%。2021年茭虾共作处理较茭白单作处理在采茭期叶的氮含量显著增加了25.74%,但在孕茭期茎中磷含量显著减少了16.76%;2022年氮肥减量、减量投喂下,茭虾共作处理较茭白单作处理在孕茭期茎的氮含量显著减少了23.75%,在分蘖期叶中磷含量显著减少了12.08%,2a全生育期同一器官的钾含量在2个处理间差异不显著。对于养分积累,2021年茭虾共作处理在分蘖期叶的氮、磷、钾积累量较茭白单作处理分别减少26.04%、27.27%、30.11%,但在采茭期茎的氮、钾积累量和叶的氮、磷积累量较茭白单作处理分别增加18.80%、38.41%和44.77%、35.71%;2022年在氮肥减量、饲料减量投喂下,茭虾共作处理在采茭期叶的磷积累量和茎的钾积累量较茭白单作处理显著增加30.0%和30.77%。关于养分分配,2种处理的茭白在孕茭期和采茭期氮素的分配均以茎、叶为主,而磷、钾元素的分配均以茎为主,茎分配比例在42%~66%。对于养分转运,2021年2种处理茭白的根、茎、叶在氮、磷转运上大多为表现为“库”器官,而在钾转运上大多表现为“源”器官;2022年氮肥减量、减量投喂下,茭白的根、茎、叶在氮、磷、钾转运量上大多表现为“源”器官。因此,在茭虾共作模式中适当减少肥料、饲料的投入,能促进形成合理的源库关系,有利于茭白产量的形成。

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。

华南地区早晚兼用型水稻产量和氮素吸收在早、晚季的差异特征

为明确华南双季稻区早晚兼用型水稻产量和氮素吸收在早、晚季的差异特征,以6个早晚兼用型水稻品种为试验材料,按当地高产栽培条件在早、晚季种植,测定其产量、产量构成、干物质积累和氮素吸收等。结果表明,早晚兼用型水稻在早、晚季种植时产量分别为6.68~7.91 t/hm^(2)和5.72~6.11 t/hm^(2);早季产量显著高于晚季,平均增幅为1.53 t/hm^(2)。相关分析表明,较高的早季产量与其有效穗数和粒重的提高有关。早、晚季干物质积累量和氮素吸收差异显著;相对于晚季,早季成熟期干物质积累量和氮素吸收平均提高25.0%和29.5%。另外,早、晚季产量与其干物质积累量和氮素吸收显著正相关。早晚兼用型水稻在早季种植时具有较高的产量、物质生产和氮素吸收能力。研究结果可为华南地区早晚兼用型水稻的丰产栽培提供理论依据。

谷子大豆间作模式对作物干物质积累分配及产量的影响

为探究适于陕北黄土丘陵沟壑区膜际栽培条件下谷子大豆种植的最佳间作方式,采用单因素随机区组设计,设置2行谷子2行大豆间作(I_(22))、2行谷子4行大豆间作(I_(24))、4行谷子2行大豆间作(I_(42))、单作谷子(SG)和单作大豆(SD)共5个处理,分析不同间作模式下谷子和大豆干物质积累与分配特点、种间竞争力及其对产量的影响。结果表明,3种间作处理均显著提高了谷子的干物质积累量,且I_(24)处理显著高于I_(42)处理,谷子干物质分配比率孕穗期为叶大于茎,成熟期穗大于叶、茎,3种间作处理穗分配比率均显著高于单作,且I_(24)和I_(22)处理显著高于I_(42)处理;3种间作处理均显著降低了大豆的干物质积累量,大豆干物质分配比率开花期为叶大于茎,成熟期荚果大于茎、叶,3种间作处理荚果分配比率均显著高于单作,各间作处理间无显著差异。I_(24)和I_(42)间作处理土地当量比分别为1.10、1.06,土地生产力提高6%~10%,具有间作优势;I_(22)间作处理土地当量比为1.00,无间作优势。间作处理下谷子较大豆表现出了更强的种间竞争力(AG>0)和产量营养竞争比率(CRG>1),且I_(24)处理显著低于I_(42)和I_(22)处理。综上所述,2行谷子2行大豆间作为陕北黄土丘陵沟壑区的最佳谷子大豆间作方式。

化控对玉米带状间作大豆主茎分枝光合特性、物质积累及产量的影响

为充分挖掘化控技术对带状间作系统中大豆的增产潜力,本研究以大豆-玉米带状间作为研究对象,以南豆25为试验材料,通过在大豆4节期(V4)叶面喷施不同植物生长调节剂[抑芽丹(MH)、吲哚-3-乙酸(IAA)、6-苄氨基嘌呤(6-BA)、24-表油菜素内酯(EBR)、三碘苯甲酸(TIBA)、烯效唑(S3307)、胺鲜酯(DTA-6)]及清水(CK),探究调节剂对大豆主茎和分枝结构上的光合特性、干物质积累分配及产量的影响。结果表明,调节剂处理提高了带状间作大豆主茎和分枝叶片SPAD值、净光合速率、气孔导度和蒸腾速率,EBR、S3307和DTA-6处理下大豆的叶面积指数、干物质积累量和群体产量显著高于CK。各调节剂中以DTA-6协调主茎与分枝生长关系的效果最好,该处理下盛荚期(R4)大豆主茎和分枝的干物质积累量分别较CK增加15.62%和30.24%,完熟期分枝荚果分配率最高。产量结果也表明,DTA-6处理下分枝粒数和百粒重达到最大,使大豆群体产量较CK提高26.01%~32.61%。综上,DTA-6能够改善带状间作大豆主茎和分枝叶片光合特性,促进干物质积累分配及产量形成。本研究为化控在带状间作大豆中的推广应用提供了理论参考与技术支撑。

播种模式对新疆小麦干物质积累和产量及水分利用效率的影响

为确定北疆小麦适宜的播种模式,以北疆主栽冬小麦品种新冬18号和新冬41号及春小麦品种新春44号和新春48号为材料,设置晚播冬小麦(10月8日播种,用B1表示)、极晚播冬小麦和冬播春小麦(10月28日播种,用B2表示)以及春播春小麦(4月4日播种,用B3表示)三种播种模式,比较分析了播种模式间小麦的生育进程、总茎数、叶面积指数、光合势、干物质积累量、经济系数、产量及水分利用效率的差异.结果表明,B2处理的冬小麦较B1处理晚熟约7d,生育期缩短162d,出苗率、最高总茎数、LAI、总光合势、干物质积累量及总耗水量分别降低27.6个百分点、17.1%、11.5%、9.6%、3.7%和15.9%,而水分利用效率提高15.7%,平均经济系数和产量与B1处理无显著差异;B2处理的春小麦较B3处理早熟7d,生育期延长约4 d,出苗率、最高总茎数、LAI和总耗水量分别降低28.1个百分点、7.6%、5.2%和12.3%,总光合势、成熟期干物质积累量、经济系数、水分利用效率和产量分别提高6.3%、4.0%、4.5%、24.0%和8.7%;B2处理下冬小麦较春小麦晚熟约4d,生育期延长约3d,出苗率和最高总茎数的平均值分别降低7.9个百分点和7.6%,产量和水分利用效率均无显著差异.极晚播冬小麦和冬播春小麦的平均产量和水分利用效率均较高,其中产量与晚播冬小麦差异均不显著,熟期接近.综合考虑高产和节水及早熟的需求.本试验条件下,冬小麦极晚播和春小麦冬播是北疆地区小麦的适宜播种模式.

播种方式对旱地春小麦产量、干物质及水分利用效率的影响

为提高新疆旱地春小麦产量及水分利用效率,筛选出适宜的播种方式,采用单因素随机区组试验,设置传统平作(T1)、起垄沟播(T2)、起垄覆膜沟播(T3)3个播种方式,研究不同播种方式下旱地的土壤含水量及春小麦的叶面积指数(leaf area index,LAI)、干物质量、产量,并进一步比较土壤贮水量、耗水量及水分利用效率等。结果表明,在抽穗期之前,T2和T3处理均可显著增加旱地春小麦的LAI和干物质量;在抽穗期之后,T3处理较T2和T1处理更有利于提高旱地春小麦的LAI和干物质量。同时,T3处理可显著提高拔节期土壤0—80 cm土层的含水量和贮水量,分别较T2、T1处理显著提高32.09%、34.64%和38.20%、38.85%;T3处理降低了播种—拔节期土壤耗水量,增加了拔节期—收获期的土壤耗水量,有利于植株中、后期的生长发育。T3处理可提高旱地春小麦的有效穗数、单穗粒数、籽粒产量、水分利用效率和降水利用效率,其中产量最高为2474.43 kg·hm^(-2),较T1、T2处理分别显著增加50.13%和50.47%;水分利用效率和降水利用效率分别显著提高48.99%、51.02%和49.41%、50.15%。综上所述,起垄覆膜沟播有利于小麦增产和水分高效利用,为新疆旱地春小麦蓄水保墒和高产高效提供了理论依据及技术参考。

不同施镁水平对红壤土花生光合特性、干物质积累和产量的影响

为探究施用镁肥(Mg)对红壤土花生生长和产量的影响,本研究以花育25为供试花生品种,通过盆栽试验,设置0、0.1、0.2、0.3、0.4 g/kg(Mg0、Mg1、Mg2、Mg3、Mg4)5个镁肥水平,研究不同施镁水平对不同生育时期花生的叶绿素含量、光合特性、镁含量、干物质积累量及成熟期荚果产量的影响。结果表明,一定范围内施用镁肥对花生全生育期的生长和产量均有明显影响,开花下针期、结荚期和成熟期植株叶片叶绿素含量均以Mg2处理最高;开花下针期Mg2处理花生叶片净光合速率、胞间二氧化碳浓度和气孔导度明显高于其他处理;结荚期和成熟期,与Mg0处理相比,Mg2处理荚果干物质积累量分别提高16.4%和18.9%,成熟期单株产量和单株饱果数分别增加15.2%和66.5%。继续增加镁肥施用量至0.3~0.4 g/kg,则明显抑制花生生长。综上,本试验条件下,花育25适宜镁肥施用量为0.2 g/kg。