Calcium-Magnesium Ca/Mg Ratios and Their Agronomic Implications for the Optimization of Phosphate Fertilization in Rainfed Rice Farming on Acidic Ferralsol in the Forest Zone of Ivory Coast

This study is a contribution to improving rice productivity on acidic plateau soils of the tropical rainforest zone. It is based on taking into account the cationic balances of the soil in order to optimize the phosphorus (P) nutrition of rice on these acidic soils, where this nutrient constitutes a limiting factor for agricultural production. Three (3) pot trials were conducted in Adiopodoumé in the forested south of Côte d’Ivoire. The interactive effects of calcium carbonate (0, 25, 50 and 75 kg Ca ha−1) and magnesium sulfate (0, 25, 50 and 75 kg Mg ha−1) were evaluated on the response of NERICA 5 rice at doses 0, 25, 50 and 75 kg P ha−1 of natural phosphate from Togo, applied only once at the start of the experiment. Additional fertilizers of nitrogen (N) (100 kg N ha−1) and potassium (K) (50 kg KCl ha−1) were added to each of the tests in a split-plot device. The test results revealed a paddy production potential of approximately 3 to 5 t⋅ha−1 for NERICA 5 on an acidic soil, under the effect of the interaction of P, Ca and Mg. The quadratic response of rice yield to the doses of these fertilizers would be more dependent on their balance, itself influenced by Ca nutrition. For the sustainability and maintenance of rice production in agro-ecology studied, it was recommended doses of 38 kg Ca ha−1, 34 kg Mg ha−1 in a Ca/Mg ratio (1/1) with intakes of 41 kg P ha−1, overall in a ratio 1/1/1 (P/Ca/Mg) more favorable to the availability of free iron considered a guiding element of mineral nutrition. Thus, these promising results should be confirmed in a real environment for better management of the fertilization of rice cultivated on acidic plateau soils in Côte d’Ivoire.

Effects of Different Row Ratios of Male and Female Parents and Application Amount of Nitrogen Fertilizer on Hybrid Wheat Seed Production and Its Component Factors

In order to screen suitable high hybrid wheat seed production technology,the split-plot experiment design was adopted and study was carried out about the effects of the different row ratios of male and female parents and application amount of nitrogen fertilizer on hybrid wheat seed production and its component factors. The results showed that the seed production increased with the increase in the number of female parent row. When the row ratio of male and female parents was 2 ∶ 6,the seed production was 3 683. 8 kg/ha; when the application amount of nitrogen fertilization was 50 kg/ha,the seed production was 3 649. 4 kg/ha; the interaction between the row ratio of male and female parents and the application amount of nitrogen fertilizer indicated that when the row ratio of male and female parents was 2∶ 6 and the application amount of nitrogen fertilizer was 300 kg/ha,the seed production reached the highest( 4160. 6 kg/ha). The row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the component factors of seed production,including the number of grains per spike,spike weight and setting percentage. When the row ratio of male and female parents was 2∶ 5,the number of grains per spike,spike weight and setting percentage were the highest at 26. 7 grains,1. 12 g,and 62. 6% respectively; when application amount of nitrogen fertilizer was 450 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 26. 0 grains,1. 08 g,and59. 2% respectively; the interaction of row ratio of male and female parents and application amount of nitrogen fertilizer had significant effect on the number of grains per spike,spike weight and setting percentage; when the row ratio of male and female parents was 2∶ 5 and the application amount of nitrogen fertilizer was 300 kg/ha,the number of grains per spike,spike weight and setting percentage were the highest at 29. 6grains,1. 24 g,and 71. 6% respectively. The number of grains per spike is the largest component factor for seed production. Increasing the number of grains per spike can increase the seed production. According to the effects of row ratio of male and female parents and application amount of nitrogen fertilizer on the component factors of seed production,the optimal condition was 2∶ 5-2∶ 6 for row ratio of male and female parents and 300-450 kg/ha for application amount of nitrogen fertilizer.

Carbon Sequestration in Soil Humic Substances Under Long-Term Fertilization in a Wheat-Maize System from North China

The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （WSS）, humic acid （HA）, fulvic acid （FA） and humin （HU） were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon （SOC） and HS （R^2=0.98, P〈0.01）. The change in the E4/E6 ratio was significantly correlated with the increased SOC （R2=0.88, P〈0.01）, HA （R^2=0.91, P〈0.01）, FA （R^2=0.91, P〈0.01） and HU （R^2=0.88, P〈0.01）. The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.

Net energy yield and carbon footprint of summer corn under different N fertilizer rates in the North China Plain

Excessive use of N fertilizer in intensive agriculture can increase crop yield and at the same time cause high carbon（C） emissions.This study was conducted to determine optimized N fertilizer application for high grain yield and lower C emissions in summer corn（Zea mays L.）.A field experiment, including 0（N0）, 75（N75）, 150（N150）, 225（N225）, and 300（N300） kg N ha–1 treatments, was carried out during 2010–2012 in the North China Plain（NCP）.The results showed that grain yield, input energy, greenhouse gas（GHG） emissions, and carbon footprint（CF） were all increased with the increase of N rate, except net energy yield（NEY）.The treatment of N225 had the highest grain yield（10 364.7 kg ha–1） and NEY（6.8%）, but the CF（0.25） was lower than that of N300, which indicates that a rate of 225 kg N ha–1 can be optimal for summer corn in NCP.Comparing GHG emision compontents, N fertilizer（0–51.1%） was the highest and followed by electricity for irrigation（19.73–49.35%）.We conclude that optimazing N fertilizer application rate and reducing electricity for irrigation are the two key measures to increase crop yield, improve energy efficiency and decrease GHG emissions in corn production.

Complementary effects of organic and mineral fertilizers on maize production in the smallholder farms of Meru South District, Kenya

Low soil fertility is a major constraint to maize production in the small holder farms of Meru South District. This is mainly attributed to the mining of nutrients due to cropping without external addition of adequate nutrients. Mineral fertilizers are expensive hence un affordable by most small holder farmers. The use of organic matter to increase and maintain soil fertility is being considered as a solution to help the low-income small holder farmers. A study was conducted in Mucwa location, Meru South District to determine the levels of complementarity between organic and mineral N amendments on maize yields and their influence on soil chemical properties. The experiment was set in a complete randomized block design (CRBD) with three replicates. The treatments were compared with the response obtained from control. The general soil fertility parameters changed slightly with Calcium, Magnesium and Potassium increasing in all treatments. The organic Carbon and total Nitrogen was higher in treatments that received sole organic N sources than in sole mineral N and a combination of organic and mineral N sources. The highest maize grain yield of 4.8 t·ha-1 and 4.2 t·ha-1 were realized from sole application of calliandra during the 2005 Short rains and 2006 Long rains cropping seasons. Generally the maize grain yields were lower in treatments with mineral N alone compared to the treatments with organics. Treatments with sole calliandra and sole tithonia had the highest benefit cost ratio (BCR), followed closely by manure treatment. More so, integration of organic and mineral N sources resulted to higher net benefit and BCR than the application of the recommended rate of mineral fertilizers. Results obtained indicated that the use of either organic or combined organic/mineral N soil amendment appear to be superior to using mineral amendment sources alone.

Yield and Quality Response of Ryegrass, Egyptian Clover and Their Mixtures to Different Sources of Fertilizers

Two field experiments were conducted during two successive winter seasons of 2008/2009 and 2009/2010 to investigate the potentialities of mixing Egyptian clover with ryegrass under bio, organic and mineral fertilization treatments and their combination to increase forage yield and quality grown under sandy soil conditions. The experiment included the combination of five mixing ratios (Egyptian clover alone, ryegrass alone, 75% Egyptian clover: 25% ryegrass, 50% Egyptian clover: 50% ryegrass and 25% Egyptian clover: 75% ryegrass) and eight fertilizer sources, which include control, organic fertilization, bio fertilization, chemical fertilizer, organic + bio fertilizer, organic + chemical fertilizer, bio + chemical fertilizer and combination of organic and chemical and bio fertilizers. The obtained results indicate the superiority of 75% E. clover: 25% ryegrass mixture fertilizedby Bio + O + N in fresh and dry forage production. On the other hand, it reported the lowest dry weight of weeds g/m2. Chemical analysis of forage plants showed that the mixture of ?75% E. clover: 25% ryegrass surpassed that of other treatments yield for crude protein, ether extract and ash. The results also revealed that the highest record of DCP, crude fiber and TDNY was obtained by forage mixture of 75% E. clover: 25% ryegrass fertilized with Bio + O + N. Such higher yield of these characters hassecured a balanced ratio which is really needed for ruminants ration.

氮、磷、钾肥对紫穗槐幼苗根叶化学计量特性的影响

探讨紫穗槐根和叶化学计量特性对养分的适应性,为豆科植物施肥和限制模式的研究提供依据,采用三因素(氮(N)、磷(P)、钾(K)),三水平(N1,N2,N3,P1,P2,P3,K1,K2,K3)的施肥处理,测定紫穗槐幼苗根和叶的碳(C)、氮、磷、钾含量,分析根和叶各元素之间的关系。结果表明,在P、K添加下,叶片比根系有更强的响应,根系对N添加有更强的反应。叶片和根N含量、根N/K和N/P随施氮水平的增加而显著增加,根P/K、叶P/K和根C/N显著降低。随着施磷量的增加,叶片N、P、K含量、根P含量、根N/K和P/K显著增加,叶N/K和叶N/P显著降低;根和叶K含量随施钾量的增加而显著增加,根N/K和P/K、叶N/K和P/K显著降低。叶P含量与根P含量、叶K含量与根K含量呈显著正相关,叶C、N含量与根C、N含量之间的关系不显著,而叶根N、P、K含量分别与相应的C/N、N/P和N/K呈显著负相关。叶和根的C/N之间的关系不显著,而叶的N/P、N/K和P/K之间的相关性显著。隶属函数分析结果表明,在紫穗槐C、N、P、K含量的累积方面,N2处理最佳。N的添加导致P对叶片和根的限制;P的添加导致N对叶片和根系的限制;K的添加并没有改变限制模式。研究结果可为紫穗槐的合理施肥和科学管理提供依据。

中心性肥胖对不孕女性体外受精-胚胎移植妊娠结局的影响

目的探讨中心性肥胖对不孕女性接受体外受精-胚胎移植后的妊娠结局的影响。方法回顾性选取2017年10月至2019年9月在温州医科大学附属第一医院生殖医学中心首次接受体外受精-胚胎移植的2801例不孕女性为研究对象。根据进入治疗周期时的BMI和腰臀比(WHR)分为正常BMI非中心性肥胖组1659例、正常BMI中心性肥胖组654例、肥胖非中心性肥胖组146例和肥胖中心性肥胖组342例,比较4组治疗过程中促性腺激素使用剂量、促排时间、获卵数、可用胚胎数及新鲜胚胎移植妊娠结局。采用多元线性回归分析中心性肥胖对促排周期获得可用胚胎数的影响,多因素logistic回归分析影响患者新鲜胚胎移植能否获得活产的相关因素。应用Kaplan-Meier生存曲线绘制各组单个取卵周期累积活产率。结果与正常BMI非中心性肥胖组相比,肥胖中心性肥胖组促性腺激素使用剂量增加,获卵数和可用胚胎数减少,新鲜胚胎移植后活产率下降,妊娠丢失率增加,单个取卵周期累积活产率下降,差异均有统计学意义(均P<0.05)。多元线性回归分析提示WHR≥0.85显著降低患者促排周期获得的可用胚胎数。不论BMI是否提示肥胖,WHR≥0.85的中心性肥胖女性,其单个取卵周期累积活产率较正常BMI非中心性肥胖组女性下降(均P<0.05)。多因素logistic回归分析发现腰围的增加会使新鲜胚胎移植后活产率降低(OR=0.978,95%CI:0.963~0.992,P=0.003)。Kaplan-Meier生存曲线显示随着胚胎移植周期数增多,4组患者单个取卵周期累积活产率比较差异有统计学意义(P<0.05)。结论中心性肥胖对女性体外受精-胚胎移植的妊娠结局造成不良影响。

配方施肥对铁心杉幼苗生长和生理生化指标的影响

【目的】旨在寻找最适合铁心杉幼苗生长的肥料配比。【方法】采用“3414”试验设计方案,设置14组肥料配比,以每组50盆的1年生铁心杉实生苗为材料,探究不同肥料配比对幼苗生长和生理生化指标的影响。【结果】与不施肥相比,合理施肥的铁心杉幼苗叶片的叶绿素含量最高提高了42.01%,可溶性糖含量最高提高了11.64%,可溶性蛋白含量最高提高了13.81%,游离脯氨酸含量最高提高了211.25%;在N_(2)P_(2)K_(1)的肥料配方下,铁心杉幼苗的苗高、根直径、地上生物量、地下生物量、总生物量及苗木质量指数达到最大值,地径、根表面积和总根长也处于中上水平。【结论】N_(2)P_(2)K_(1)(每盆施1.0 g N、1.0 g P、0.5 g K)是铁心杉幼苗最佳的施肥配方。

有机无机肥配施对江苏滨海盐碱土农田生产力和碳库的影响

[目的]有机肥施用是江苏滨海轻度盐碱地主要的改土提质技术,本试验通过研究在有机替代模式下夏玉米种植系统农田生产力和土壤碳库的变化特征,探索在粉垄耕作模式下有机肥还田同氮肥减量的最佳比例。[方法]按照等氮量投入原则,以当地氮肥施用(CK)为对照,设置25%有机肥+75%氮肥(CT25)、50%有机肥+50%氮肥(CT50)、75%有机肥+25%氮肥(CT75)、有机肥全量替代氮肥(CT100)处理,开展粉垄耕作模式下不同比例有机肥替代氮肥玉米种植田间试验,对玉米农田生产力和土壤碳库指标进行测定。[结果]与氮肥全量施用相比,有机肥替代化肥比例在25%~50%时,玉米籽粒产量可增加8.74%~11.21%,其中CT25处理的玉米光合速率(P_(n))、气孔导度(G_(s))、蒸腾速率(T_(r))、胞间CO_(2)浓度(C_(i))显著增加,土壤全氮、全磷、全钾、碱解氮、速效磷、速效钾含量均较单施氮肥显著增加,有机替代比例超过50%以上时玉米产量和土壤养分较纯施氮肥无显著变化。相较于纯施氮肥,有机肥替代比例在25%~75%时土壤碳储量提升9.47%~14.61%,这主要依赖于土壤有机碳含量和容重的显著增加。土壤有机碳含量和玉米产量呈显著的正相关关系。[结论]粉垄耕作模式条件下,有机肥替代氮肥在25%~50%可以显著改善土壤理化性质,增加土壤碳储量,提升农田生产力,可作为江苏滨海旱作玉米种植推荐施肥技术。

适宜氮磷钾用量和配比协同促进盆栽牡丹营养和生殖生长

【目的】牡丹是我国著名的木本观赏植物,施肥不平衡严重影响盆栽牡丹的生长和观赏效果。研究开花前后氮、磷、钾不同施用量和配施比例对盆栽牡丹生长的影响,确定适宜的氮、磷、钾施用量及配比,为盆栽牡丹精准施肥提供理论依据。【方法】本研究以5年生牡丹‘紫二乔’为供试材料,采用“3414”不完全正交回归设计进行盆栽试验,结合隶属函数法评价牡丹的生长状况,利用肥料效应模型拟合牡丹植株的综合隶属函数值与施肥量之间的数学关系,得出牡丹最佳生长的氮、磷、钾肥推荐施肥量。【结果】牡丹开花前后施用氮磷钾肥显著影响植株株高、茎粗、冠幅、花径和单株花数(P<0.05),适宜氮磷钾用量和配比促进盆栽牡丹营养和生殖生长的协同提高。氮、磷、钾三因素配合处理的牡丹综合隶属函数值均大于缺素处理,缺素处理又大于无肥处理,N_(2)P_(2)K_(2)处理的综合隶属函数值(0.73)是N_(0)P_(0)K_(0)的3.17倍。氮磷钾对牡丹综合生长的影响表现为氮>磷>钾。氮、磷、钾肥对牡丹营养和生殖生长存在明显交互作用,任一肥料水平的过量或不足均会抑制牡丹植株生长,降低观赏效果。采用一元二次、二元二次、三元二次肥料效应函数方程拟合牡丹的综合隶属函数值和施肥量,二者相关性均达显著水平,综合各肥料效应函数方程的推荐用量及相应的综合隶属函数值,得出牡丹开花前后氮(N)、磷(P_(2)O_(5))、钾(K_(2)O)的最优推荐施肥量分别为4.21、2.07、2.52 g/株,适宜的氮、磷、钾施肥比例为1∶0.49∶0.60。【结论】开花前后施用适量的氮、磷、钾肥可提高牡丹的农艺性状,促进牡丹的营养和生殖生长协同提高。氮、磷、钾的最优推荐施肥量为4.21、2.07、2.52 g/株,适宜的氮、磷、钾施肥比例为1∶0.49∶0.60。

磷肥有机替代、秸秆还田对棉花养分吸收和磷肥利用效率的影响

为探究磷肥有机替代、秸秆还田对棉花养分吸收、磷肥利用效率及棉花产量的影响,本研究基于国家灰漠土肥力与肥料效益监测站5年田间微区棉花连作定位试验,以7种施肥措施为样本,于2022年棉花成熟期开展棉田土壤田间调查研究。结果表明,磷肥有机替代和秸秆还田均能提升棉株氮磷钾养分吸收,各器官氮素平均含量在1.75~40.90 g·kg^(-1)之间,磷素平均含量在1.46~11.28 g·kg^(-1)之间,钾素平均含量在3.11~25.03 g·kg^(-1)之间。综合肥料投入和养分吸收,50%的磷肥有机替代和秸秆还田最能增强棉株吸氮能力和促进干物质积累,50%的磷肥有机替代对棉株吸磷能力最强且最有利于实现棉花节肥增钾的效果。棉株各器官N:P变化范围为1.20~12.01,磷肥有机替代和秸秆还田使茎、叶、蕾/铃/壳的N∶P明显降低,棉株生物量、籽棉产量随茎、叶、蕾/铃/壳N∶P的降低而增加,本试验棉花生长更倾向于受N、P共同限制。磷肥利用率随有机替代量的增加从12.54%提升到33.04%,土壤磷素盈余量随有机替代量的增加从28.20 kg·hm^(-2)降低到19.66 kg·hm^(-2)。研究表明,在北疆灰漠土棉区采用50%磷肥有机替代,即施磷(P2O5)60.0 kg·hm^(-2)和配施羊粪9 784.8 kg·hm^(-2),对棉花产量、生物量、养分吸收的综合效应最优,值得推广应用。

有机肥部分替代化肥对河套灌区土壤有机碳和向日葵产量的影响

【目的】揭示河套灌区不同种类和比例有机肥替代化肥对土壤肥力和向日葵产量的影响,筛选土壤有机碳与向日葵产量协同提升的有机无机肥配施模式。【方法】设置不施肥(CK)、常规施化肥氮(MN)、20%羊粪有机肥氮+80%化肥氮(SN1)、40%羊粪有机肥氮+60%化肥氮(SN2)、20%牛粪有机肥氮+80%化肥氮(CN1)、40%牛粪有机肥氮+60%化肥氮(CN2)、20%猪粪有机肥氮+80%化肥氮(PN1)、40%猪粪有机肥氮+60%化肥氮(PN2)8个处理,分析不同种类和比例有机肥替代化肥对土壤有机碳含量、全氮含量、铵态氮浓度、硝态氮浓度、无机氮浓度、团聚体组成以及向日葵植株性状、地上部生物量、产量、氮肥利用率的影响。【结果】与MN处理相比,施用羊粪有机肥氮对土壤有机碳含量无显著影响(P>0.05),牛粪或猪粪有机肥氮可显著提高土壤有机碳含量(P<0.05),且提升效应随有机肥用量的增加而增加;CN1处理土壤铵态氮、硝态氮和总无机氮浓度分别显著增加9.7%、6.0%和7.6%(P<0.05);PN2处理土壤大团聚体质量比例显著提高29.3%(P<0.05)。与MN处理相比,CN1和PN1处理向日葵盘径和千粒重显著提高5.8%和4.0%(P<0.05);向日葵地上部生物量显著增加4.6%和12.8%(P<0.05);产量和氮肥利用率显著提高(P<0.05),其中CN1处理增幅最高,为14.3%和66.1%。【结论】20%牛粪/猪粪有机肥氮+80%化肥氮处理有利于土壤有机碳含量的提高以及向日葵盘径、千粒重、产量、氮肥利用率的增加,能够实现土壤有机碳含量和向日葵产量的同步提升,可作为河套灌区低肥力耕地的适宜有机无机肥配施技术模式。

生物炭与有机无机肥配施对土壤质量的影响

为探究生物炭与有机无机肥配施对土壤以及作物产量的影响,在温室中以小麦为栽培对象,以化肥与有机肥、生物炭配施的不同比例安排7个处理:CK1(不施肥)、 CK2(化肥)、 T1(100%化肥+生物炭)、 T2(80%化肥+有机肥)、 T3(80%化肥+有机肥+生物炭)、 T4(60%化肥+有机肥)和T5(60%化肥+有机肥+生物炭),探究土壤基本理化性质、酶活性以及微生物代谢功能对不同施肥方式的响应.结果表明,不同施肥方式对土壤养分影响显著.添加了有机肥、生物炭可显著提高养分含量,且T3养分含量几乎均为最高.添加了有机肥与生物炭的处理,土壤蛋白酶与蔗糖酶的活性得到显著提升,而对于过氧化氢酶的活性提升效果不明显.随着施加有机物料比例提升,土壤微生物的群落多样性及其对碳源代谢能力也有显著升高.根据土壤质量指数(Soil Quality Index, SQI)的排序:T3>T4=T5>T1>CK2=T2>CK1,施加有机物料能够提升土壤质量和作物产量,提升强度随着比例升高呈先增加后降低的趋势.综上,施加有机物料能提升土壤养分含量、酶活性及土壤微生物碳源代谢能力,且影响强度均与施加比例相关.在N,P2O5,K2O施用量分别为225, 90, 90 kg/hm2条件下,20%减量化肥与有机肥(3 000 kg/hm2)和生物炭(10 000 kg/hm2)配施能够有效改良土壤并增产.

控释掺混肥对小麦–玉米轮作体系产量、氮肥利用效率及氨挥发的影响

【目的】针对华北平原冬小麦-夏玉米轮作体系氮肥施用量大、氮肥利用率低、氮素损失严重等问题,探讨不同配比的控释掺混肥减氮和一次性施肥对周年作物产量、氨挥发损失和施肥经济效益的影响,确立麦玉轮作体系轻简高效和环境友好的施肥技术。【方法】于2022—2023年,在山东省德州市现代农业科技园区开展田间试验。冬小麦和夏玉米均设不施氮对照(CK)、农户习惯施氮(FFP)、优化施氮(OPT)、CRBF1(包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为5∶5和3∶7)和CRBF2(包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为7∶3和5∶5),共5个处理。基施和追施肥后,监测了氨挥发量、强度和损失率。分析了作物干物质积累和产量、氮素吸收量和氮肥利用效率,并计算了施肥经济效益。【结果】与FFP处理相比,CRBF1和CRBF2处理的夏玉米、冬小麦和周年产量差异不显著;CRBF1和CRBF2处理夏玉米氮肥偏生产力提高了8.87~9.86 kg/kg,CRBF2处理玉米氮肥回收率提高了48.4%(P<0.05);CRBF1和CRBF2处理冬小麦季氮肥回收率、氮肥农学利用率和氮肥偏生产力分别提高了30.3%~37.2%、5.22~5.77 kg/kg和6.52~7.06 kg/kg(P<0.05)。与FFP和OPT处理相比,CRBF1和CRBF2处理的肥料+施肥人工投入减少381~960元/hm^(2),周年净收入增加1208~2654元/hm^(2)。CRBF1和CRBF2处理的周年氨挥发损失量、损失强度和损失率较FFP处理分别降低了69.7%~71.9%、72.0%~74.5%和90.0%~94.1%(P<0.05)。【结论】包膜尿素与普通尿素在冬小麦、夏玉米季按照5∶5、3∶7,或者按照7∶3、5∶5的比例掺混一次性基施,均可在减少氮肥用量和施肥劳力投入的条件下,确保周年作物产量稳定,提高生产效益,并显著降低氨挥发损失,是华北平原冬小麦-夏玉米轮作系统高产高效、轻简施肥的有效氮肥施用技术。

促生菌剂及有机肥的添加对高寒草甸土壤酶活性的影响

【目的】探究促生菌剂及有机肥施用对高寒草甸土壤环境的影响,为促生菌剂在天然草甸中施用及高寒地区草甸生态系统的管理提供理论依据。【方法】以甘南玛曲高寒草甸为研究对象,设计随机区组研究,设置对照(CK)、促生菌剂(PG)、有机肥(OF)、促生菌剂和有机肥1∶1配施(PG+OF)4个处理,通过测定土壤理化性质、微生物量碳(MBC)、微生物氮(MBN)、微生物磷(MBP)和水解酶活性(AP、βG、CBH、βX、NAG),研究促生菌剂及有机肥对高寒草甸土壤酶及酶化学计量比的影响。【结果】与对照(CK)相比,处理PG、OF及PG+OF的电导率显著降低,MBC、N、P含量显著升高;处理PG+OF高寒草甸土壤的MBN含量显著高于其他处理,即促生菌剂和有机肥相互作用显著提升土壤中微生物数量。与CK相比,处理PG、OF及PG+OF显著促进水解酶活性升高,MBC、MBP、MBN、EC是土壤中酶活性及酶化学计量比变化的重要驱动因子,不同处理间酶化学计量比差异显著。【结论】促生菌剂及有机肥施用显著增加土壤中微生物数量,增强土壤中微生物活性,且对缓解土壤内碳源、磷源缺失具有正向作用,配施促生菌剂和有机肥对土壤的改良效果最为显著。

等碳量不同有机物料添加对红壤团聚体组分分布及有机碳、氮含量的影响

由于土壤理化性质不同,不同肥力的红壤上适宜的有机物料种类可能存在差异。为精准分类指导不同肥力红壤选择适宜的有机物料种类,选择长期进行花生、油菜轮作的红壤旱地,采集0~20和>20~40 cm深度土壤样品,分别代表高肥力和低肥力土壤,设置不施有机碳(C0)以及施用油菜秸秆碳(OSC)、水稻秸秆碳(RSC)、玉米秸秆碳(MSC)、猪粪碳(PMC)处理,其中各有机物料处理的碳投入量相同,进行连续90 d的避光培养,测定不同处理团聚体组分及有机碳、氮含量,分析有机物料投入C/N比与团聚体组分C/N比的相关关系。结果表明:(1)与C0对照相比,各有机物料处理均显著提高了>2 mm团聚体比例。在高肥力土壤中,OSC、RSC、MSC和PMC处理>2 mm团聚体组分比例分别增加217.89%、283.97%、286.63%和210.63%,低肥力土壤中上述处理的增幅分别为72.25%、84.45%、72.11%和46.47%。(2)有机物料投入后,>2、>0.25~2、≥0.053~0.25和<0.053 mm团聚体组分有机碳含量均显著提升,但不同肥力土壤中各有机物料处理下团聚体组分有机碳的增幅差异较大,以>2 mm团聚体组分有机碳为例,高肥力土壤表现为RSC和MSC处理较高,而低肥力土壤则表现为OSC处理较高。(3)高肥力和低肥力土壤中添加不同有机物料均显著增加了>0.25~2和<0.053 mm团聚体组分全氮含量,且各处理均大体呈现出PMC处理最高的趋势。(4)在高肥力和低肥力土壤中添加不同有机物料均增加了团聚体组分C/N比,但高肥力和低肥力土壤中存在明显分异。以>0.25~2 mm团聚体组分C/N比为例,高肥力土壤表现为OSC、RSC和MSC处理较高;而低肥力土壤则表现为RSC和MSC处理较高,且大体呈现出PMC处理下土壤团聚体组分C/N比显著低于其他有机物料处理的趋势。(5)高肥力土壤中,提高有机物料C/N比可显著增加土壤>2和>0.25~2 mm团聚体组分C/N比;而低肥力土壤中,仅>0.25~2 mm团聚体组分C/N比与有机物料投入C/N比呈显著正相关。结合拟合方程的斜率分析发现,当投入有机物料的C/N比增加时,高肥力土壤中>0.25~2 mm团聚体组分C/N比的增幅明显小于低肥力土壤。与猪粪相比,秸秆类有机物料对团聚体碳、氮积累的促进效果较好。建议参考土壤肥力水平精准调控投入有机物料的C/N比,以期合理提升土壤团聚体组分的C/N比。

不同施肥处理对金瑞油桃产量和品质的影响

为解决山西油桃园施肥不合理的现象,筛选出适合当地油桃生产的施肥配比和施肥量,以4年生金瑞油桃为试验材料,磷肥固定,氮肥和钾肥各设置4个梯度,以不施肥为对照,研究不同施肥处理对运城地区金瑞油桃产量和品质的影响。结果表明,适量增施氮肥和钾肥均可显著增加油桃的横纵径和单果质量,提高油桃可溶性固形物、可溶性总糖和维生素C含量,降低总酸度,提高果实糖酸比,改善果实品质和口感;但施氮量超过240 kg/hm^(2)时,过量的氮肥会降低油桃可溶性固形物、维生素C和可溶性糖含量,不利于油桃品质和产量的提升。与不施肥对照相比,处理N_(2)PK_(2)(N 240 kg/hm^(2)、P_(2)O_(5)120 kg/hm^(2)和K_(2)O 240 kg/hm^(2))和处理N_(2)PK_(3)(N 240 kg/hm^(2)、P_(2)O_(5)120 kg/hm^(2)、K_(2)O 360 kg/hm^(2))增产率分别为28.77%和31.34%,增产值分别为25 440元/hm^(2)和27 720元/hm^(2),经济效益显著高于其他处理。通过构建施肥模型,试验地金瑞油桃的钾肥最佳施用量为398 kg/hm^(2)。综上,不同施肥配比和施肥量对油桃内在品质和产量有较大影响,试验地油桃适宜的氮、磷、钾施用比例为1.0∶0.5∶1.0~1.5,推荐施肥量分别为N 240 kg/hm^(2)、P_(2)O_(5)120 kg/hm^(2)、K_(2)O 240~360 kg/hm^(2)。

配比施肥对‘聊红’椿幼苗生长及光合特性的影响

为探究氮磷钾配比施肥对‘聊红’椿幼苗生长及光合特性的影响,以一年生‘聊红’椿幼苗为试验材料,采用L16(43)正交设计进行盆栽试验,旨在为‘聊红’椿幼苗的科学施肥提供参考依据。结果表明,T9组的各生长指标、质量指数及叶片的叶绿素含量、净光合速率(Pn)、气孔导度(Gs)和胞间CO_(2)浓度(Ci)均为各处理组中的最大值,T7组的蒸腾速率(Tr)为各处理组中的最大值。氮肥对幼苗各生长指标和光合指标有极显著影响,对苗木质量指数有显著影响。钾肥对净光合速率、气孔导度和胞间CO_(2)浓度有极显著影响,对叶面积、地下生物量、总叶绿素含量和叶绿素a含量有显著影响。磷肥对叶面积、气孔导度和蒸腾速率有显著影响。氮磷钾三因素对株高、地径、叶面积、地上生物量、总生物量、质量指数、总叶绿素、叶绿素a含量、净光合速率、气孔导度和胞间CO_(2)浓度的影响效应为N>K>P,对叶绿素b含量和蒸腾速率的影响效应为N>P>K,对地下生物量的影响效应为K>N>P。经隶属函数分析后可知T9组(氮肥6 g/株,磷肥3 g/株,钾肥4.5 g/株)为最佳施肥方案。

施氮水平对普通大蓟马繁殖及子代性比的影响

为了评价施氮(N)水平对普通大蓟马(Megalurothrips usitatus)繁殖及其性比的影响,采用盆栽法种植豇豆(Vigna unguiculata),分别按低N(0 kg·hm^(-2))、中N(160 kg·hm^(-2))和高N(320 kg·hm^(-2))水平于苗前土施尿素,用叶盘法在室内单头饲喂已交配的1日龄雌虫,以嫩豇豆荚饲养其子代,观察亲代雌虫的繁殖与存活状况、子代的数量与性别。结果显示:与低N和中N处理相比,高N显著延长亲代雌虫的存活天数和产卵期,缩短产卵前期,提高产卵量和日产卵量。低N、中N和高N处理的子代雄性比分别为0.70、0.59和0.45,彼此之间差异显著。子代雌虫数量随施N水平的提高而增加,高N处理的子代成虫数显著大于低N和中N。施N对子代存活率没有影响。以上结果表明,施N水平能影响普通大蓟马的生长繁殖和性比,偏施N肥有利于普通大蓟马的繁殖,促使子代性比偏雌。