温度和降水对中国草本植物、灌木和乔木养分重吸收特征的影响

为进一步完善我国植物养分循环模型,收集了51篇国内外中英文文献进行meta分析,研究了草本植物、灌木、乔木氮(N)、磷(P)重吸收特征的差异及温度和降水量对其产生的影响。结果表明:(1)我国草本植物、灌木、乔木凋落叶平均N含量分别为9.05,14.91,12.72 mg/g,草本植物、灌木、乔木凋落叶平均P含量分别为0.50,0.79,0.76 mg/g。草本植物、灌木、乔木的平均N重吸收率分别为64.16%,51.97%,35.82%,草本植物、灌木、乔木的平均P重吸收率分别为65.51%,46.74%,41.72%;(2)草本植物调落叶N,P含量显著低于灌木和乔木,但草本植物N,P重吸收率显著高于灌木和乔木,灌木N重吸收率显著高于乔木,灌木的其他养分重吸收特征与乔木没有显著差异;(3)3种生活型植物凋落叶N和P含量与年均温呈正比,而N重吸收与年均温呈反比,P重吸收率与年均温不相关。3种生活型植物凋落叶N含量和N重吸收率分别与年均降水量呈正比和反比,凋落叶P含量和P重吸收率均与年均降水量不相关。本研究中草本植物较高的养分重吸收率可能说明其相较灌木和乔木更新速率更快,不同生活型植物对生境具有不同的养分适应策略。该研究中,N的重吸收相较于P受降水和温度的影响更大,这意味着气候梯度上植物N吸收和利用的策略可能比P更灵活。植物的氮、磷重吸收特征与温度和降水的响应关系可能反映了植物对气候梯度上水热条件的适应性差异。

平衡施肥毛竹林叶片营养与土壤肥力及产量的回归分析

对奉新县平衡施肥毛竹林的叶养分含量与土壤肥力及产量的相关性进行研究。结果表明:不同年龄集约经营竹林毛竹叶片养分含量变化规律与一般竹林基本一致。I度竹嫩叶的N、P、K元素含量均高于其他各度竹;Ca、Mg、S含量随竹龄增大而增大;微量养分元素Mn、Zn含量随竹龄变小而减少。土壤中影响竹叶N素含量的主要因子是有机质、速效P、活性酸、速效N和全K。土壤中影响竹叶P素含量的因子按其与竹叶中P含量的相关关系从大到小排序为:活性酸>盐基代换量>速效K>全K>速效Ca>速效P>速效N>pH值。影响竹叶中K含量的因子主要是全N、速效N、速效P、全K及活性酸,它们与竹叶中K含量的相关关系从大到小排序为:速效P>全K>速效N>活性酸>全N。施肥能快速补充竹叶养分,是竹林持续经营的保障。

黄竹叶片营养与土壤肥力及产量的相关研究

为科学合理施肥及集约经营管理黄竹林提供参考,对赣县大田乡不同配方施肥黄竹林的叶片养分含量与土壤肥力及产量的相关性进行研究。结果表明:施肥可明显提高竹林土壤的供肥能力,快速补充竹叶养分,增加竹林产量,而不同配方肥中又以矿渣肥2效果最好。影响竹叶N素含量的主要肥力因子及其影响顺序为:全N>速效N>有机质>全P。影响竹叶P素含量的肥力因子及其影响顺序为:速效K>全N>速效P>全K。影响竹叶中K含量的肥力因子及其影响顺序为:全N>全P>全K>速效N。黄竹竹叶N元素含量与产量呈显著正相关,黄竹竹叶中N元素含量的临界值为20.46 g/kg,最适值为22.94 g/kg,可用于黄竹营养诊断。

利用苎麻叶发展养殖业

我国是世界上苎麻种植面积最大的国家,产量位居首位。历年苎麻种植面积达54万公顷.苎麻叶资源极为丰富。过去苎麻叶一般被当作肥料埋入地下。没有得到充分利用。苎麻叶养分含量丰富,养分种类齐全。干苎麻叶粗蛋白质含量高达20.5%,粗脂肪含量6.7%,磷含量0.39%,钙含量4.6%,总能量4.04兆卡/千克。苎麻叶含有人畜必需的8种氨基酸。

不同养分组合下玉米肥料利用率试验

不合理的施肥会导致农业生产面临增肥不增产、土壤养分过量累积、养分利用率低和环境污染等问题,提高作物产量和养分利用率是农业可持续发展的关键。玉米是我国三大粮食作物之一,在我国农业生产中占有重要地位。河南省滑县是豫北粮食生产大县,农民种植的秋季作物主要是玉米,玉米增产增收对滑县农业生产影响较大。2022年滑县为推广绿色节本增效的农业增产增收新理念,进一步推动全县玉米持续健康发展,开展了不同养分组合下玉米肥料利用率试验。试验结果表明,玉米在氮、磷、钾均施用的情况下产量最高,纯效益最高,但养分吸收量却不是最高,说明科学合理施肥的重要意义;氮、磷、钾混合施用可在保证玉米增产增收的情况下最大限度地减少玉米对耕地生态环境的污染,且肥料养分吸收间存在拮抗作用。从玉米养分的吸收情况来看,玉米在不施肥的情况下也会从土壤中吸收大量营养,说明培肥地力对玉米高产高效的重要性,开展耕地保护性施肥研究十分重要。

Nutrient Application Model Affects the Contents of Chlorophyll and Carotenoid in Functional Leaves of Early Rice

The objective of this study was to investigate the effects of different nutri-ent application models on the contents of chlorophyl and carotenoid in the functional leaves of early rice. Using rice cultivar Xiangzaoxian45 as experimental materials, the experiment was performed by designing 6 treatments, i.e., T1 （fertilization without nitrogen）, T2（local conventional fertilization）, T3（fertilization for high yield and high effi-ciency）, T4 （fertilization for super high yield）, T5 （fertilization application for super high yield and high efficiency A） and T6 （fertilization application for super high yield and high efficiency B） in two experimental plots Yiyang and Xiangyin. The results showed that T3 respectively increased the contents of chlorophyl and carotenoid at fil ing stage by 29.27%, 38.20% and 13.16%, 30.12% in Yiyang and Xiangyin, as wel as yield of early rice by 4.20%, 4.80% to T2 on the condition of saving 20% ni-trogen fertilizer. Additional y, T5 and T6 on the condition of saving 16.7% nitrogen fertilizer by T4 increased the contents of chlorophyl and carotenoid of fil ing stage by 53.91%, 53.73% and 35.95%, 37.47% in Yiyang and Xiangyin, as wel as yield of early rice by 16.60%, 18.75% to T2 in Yiyang; increased the contents of chlorophyl and carotenoid at fil ing stage by 57.82%, 56.80% and 54.88%, 57.03% in Yiyang and Xiangyin, as wel as yield of early rice 10.10%, 6.75% to T2 in Xiangyin. More-over, there was a significant correlation or an extremely significant correlation be-tween yield and the contents of chlorophyl and carotenoid at different soil fertility level （P〈0.05 or P〈0.01）. Therefore, nutrient application plays an important role in the contents of chlorophyl and carotenoid in the functional leaves of early rice.

Changes of Soil nutrients and Tobacco Quality in Linli County and Some Suggestions on Fertilization

In order to find out the main nutrient content of tobacco planting soil and the changing characteristics of tobacco quality in Linli County,the sampling survey data of tobacco planting soil samples in Linli in 2000 and 2015,and the main chemical components,appearances and sensory qualities and physical indexes of B2F and C3F tobacco leaves from 2000 to 2015 were comprehensively analyzed and evaluated.The results showed that:the available phosphorus increased by 6.10%per year and the pH value of tobacco planting soil increased in a small range year by year,the organic matter content decreased year by year,the alkali hydrolyzable nitrogen showed a downward trend,and the water-soluble chlorine showed a rapid downward trend;the soil fertility index(SFI)was at the"high"level;in 2000—2015,the quality of tobacco leaf was relatively stable and the quality was good.In Linli tobacco planting area,the application of nitrogen control,phosphorus reduction and chlorine supplement and increase of organic matter could help us achieve the goal of high quality and efficiency of tobacco production.