不同坡位和施肥量对马尾松幼林生长的影响

通过选择立地条件基本一致的林地,采用不同坡位和施肥量进行马尾松幼林生长量对比试验。结果表明:坡位对马尾松幼林生长产生极显著影响,生长量大小依次为:下坡中坡上坡,其中下坡8年生马尾松的平均胸径、平均高分别为8.7cm、7.03m;施肥量多少对马尾松的生长量有影响,生长量大小依次为:施肥2次施肥1次无施肥,但由于在造林初期施肥,对其生长影响未达到显著差异。     

严重侵蚀红壤封禁管理措施马尾松生长过程特点

对严重退化红壤地经过封禁管理的马尾松的树高、胸径、材积生长特点进行研究，结果表明：封禁管理的马尾松树高、胸径、材积生长量均大大高于未治理的对照地，治理效果较为显著。封禁管理的马尾松树高、胸径、材积生长特点是治理后4～11a生长速度最快，其连年生长量和平均生长量均在此期间达到最大值，11a后，生长速度开始下降；而单株材积(去皮)总生长量初期增长较慢，后期增长较快，单株材积(去皮)连年生长量和平均生长量也在11a后有下降趋势，但单株材积仍未达到数量成熟龄。这种生长过程说明初期的治理措施在治理2～3a后，马尾松才表现出明显的生长效益，而10a后，马尾松的生长基本靠已恢复一定功能的生态系统来维持，但地力仍然较为贫瘠，生长量开始下降。     

退化红壤不同治理模式马尾松生长特点分析

对福建省长汀县花岗岩红壤区严重侵蚀地 3种治理模式的马尾松林分进行生长过程分析 ,结果表明 ,前期合理的水土保持工程措施和施肥措施为马尾松的正常生长创造了条件 ,3种模式的治理措施在初期对马尾松的生长都有很大的促进作用 ,其中 ,模式 对马尾松的生长促进效果最好 ,模式 的效果最差 ,随着时间推移和肥力的耗竭 ,马尾松的生长又趋退化 ,其中以模式 的效果维持时间最长 ,模式 最短 ,效果也最差。因此合理的水土保持工程措施和施肥措施是治理严重侵蚀退化土壤的必要手段 ,而后期如何进行调控管理以加快生态系统的恢复是今后在类似地区亟待研究的问题。     

退化红壤不同治理模式马尾松生长特点分析

对福建省长汀县花岗岩红壤区严重侵蚀地3种治理模式的马尾松林分进行生长过程分析,结果表明,前期合理的水土保持工程措施和施肥措施为马尾松的正常生长创造了条件,3种模式的治理措施在初期对马尾松的生长都有很大的促进作用,其中,模式对马尾松的生长促进效果最好,模式的效果最差,随着时间推移和肥力的耗竭,马尾松的生长又趋退化,其中以模式的效果维持时间最长,模式最短,效果也最差。因此合理的水土保持工程措施和施肥措施是治理严重侵蚀退化土壤的必要手段,而后期如何进行调控管理以加快生态系统的恢复是今后在类似地区亟待研究的问题。     

花岗岩侵蚀劣地马尾松残林改造途径的研究

该研究选择１０种优良速生的牧草，绿肥和薪材树种，采用林间套种的种植方式，组成松草，松肥和松薪混交３种技术措施对花岗岩侵蚀劣的马尾松残林进行改造。重点研究分析了各改造措施对马尾松生长和土壤理化性质的影响及经济效益的高低。结果表明；松草，松肥，松薪混交改造花岗岩侵蚀劣地的马尾松残林，见效快，改土保水效果好，其经济上是合理可行的。     

红壤侵蚀退化地马尾松幼苗生长及养分利用效率对施肥的响应

马尾松是南方红壤侵蚀区的先锋树种,由于受土壤贫瘠的限制,植物生长缓慢.以树龄1年的马尾松为研究对象,研究了不同施肥处理对马尾松的生长特征以及生物量、植株养分含量和养分利用效率的影响.设置了1个对照(不施肥,CK)和3种施肥方式:单施复合肥(0.94,1.89,3.56 g);复合肥与微生物菌肥混施((0.94+8.00...     

施用新型肥料对幼龄期马尾松人工林生长的影响

为科学评价新型肥料对幼龄期马尾松人工林生长的影响,本研究以广西国有派阳山林场鸿鸪分场造林点的幼龄期马尾松人工林为研究对象,采用随机区组试验设计,设置袋控缓释肥、生物质炭基肥、 非袋控肥和不施肥4种处理方式,跟踪测定林木生长状况.结果表明:对于广西国有派阳山林场鸿鸪分场的幼龄期马尾松人工林而言,施用新型肥料的效果均优于非...     

施肥对马尾松土壤磷形态的影响

采用室内盆栽试验研究了不同施肥处理下马尾松土壤磷形态,结果表明:施入P肥后土壤中无机磷的含量产生了变化,施入PK后根际土和非根际土土壤中的速效磷含量都有增加;除施入K、PK外,施肥后根际土和非根际土中Al-P的含量都比未施肥的高;施肥后Fe-P的变化比较大,而Fe-P的减少是由于南方土壤中的铁大多是以高价存在,易发生氧化还原反应;O-P是一种无效磷,施肥后土壤中的O-P含量均沉积于土壤而比对照的高;施入N、P、K、PK、NK、NPK后降低了两种土壤中Ca-P的含量。因此,为了促进马尾松的生长发育,可以给马尾松增施NP、PK、NPK肥。     

龙洞河流域马尾松群落结构及改造技术的研究

对龙洞河流域马尾松群落结构研究结果表明 ,龙洞河流域马尾松群落结构简单且物种多样性低 ,病虫害严重 ,生产力低下。并提出马尾松群落改造的原则、措施和模式     

马尾松常见病虫害防治方法探究

马尾松为典型的针叶树,对环境的适应能力很强,在干旱、贫瘠的土地上依然能快速生长,且经济价值很高,应用范围也比较广,建筑、造纸、家具等领域都在使用马尾松。因此,种植马尾松能给地区的经济发展带来促进作用。但是,马尾松种植过程中不可忽视的问题就是病虫害问题,严重影响了马尾松的生长。基于此,从马尾松常见的病虫害入手,分析现存的病虫害给马尾松生长造成的影响,并提出相应的防治措施。     

Düngung,N-Umsatz und Pflanzenwachstum in ihrer Wirkung auf die langfristige Protonenbilanz von Böden

Influence of fertilization, nitrogen transformation and plant growth on the long-term proton balance in soils In view of results of recent publications the influence of fertilization, nitrogen transformation and plant growth on proton balance in soil is discussed. One reason, why acidity in the soil increases after plant growth can be traced back to the fact, that plants take up more N-free cations than N-free Anions from the soil. Thus the more nitrogen fertilization as well other fertilization practices will increase plant yield the more the process of soil acidification will be enhanced. There ist no influence on soil pH by forms of applied fertilizer nitrogen like NH₄NO₃, HNO₃, NH₄OH, urea or biologically fixed N. However, accompanying ions of nitrogen fertilizers depending whether they are metal cations or sulfate or chlorid anions will decrease or increase proton production. For the calculation of the amount of produced acid in the soil during the uptake of nutrients by plants the yield of the plants and the alcalinity of plant ash will be needed. The calculation of the amount of produced acid both from the fertilization and the plant growth will be falsified by the unknown amount of nitrate which is leached beneath the rooting zone.     

Nitrogenase activity (Acetylene reduction) during the growth cycle of spring barley (Hordeum vulgare L.)

The nitrogenase activity (C₂H₂-reduction) was measured during the growth cycle of field grown spring barley in soil cores both with and without barley plants, and at two levels of nitrogen application, 30 and 120 kg N ha^?1 year^?1 respectively. The main purpose of the investigation was to study the effects of the growing barley plants on nitrogenase activity in the soil, and temperature and moisture contents were kept constant in all experiments. Therefore, the results cannot be used to calculate actual amounts of fixed nitrogen in the field, but should be considered rather as potential values. The nitrogenase activity was found to vary during the growth cycle, and seemed to be correlated to the photosynthetic activity of the plants. Relatively low nitrogenase activity was found in the early growth stages, and the activity increased up to a maximum in the late reproductive stage, followed by a rapid decrease during the grain filling stage. The mean values of nitrogenase activity in samples without barley plants and with barley plants were 40 and 78 nmoles C₂H₄ g soil dwt^?1 24 h^?1 respectively. The positive effect of barley plants on nitrogenase activity was stronger at 120 kg N than at 30 kg N fertilization. As a mean of the whole growth cycle the ratio between samples with and without barley plants was 1.7 with 30 kgN and 2.3 with 120 kg N fertilization. The inhibitory effect of nitrogen application on nitrogenase activity was measurable until 6–7 weeks after application, and it was strongest in cores without plants.     

Fixation and transfer of nitrogen by white clover to ryegrass

Abstract. ¹⁵N₂ was used in a sealed controlled environment chamber to investigate the transfer of fixed nitrogen from white clover to perennial ryegrass growing in soil in pots. There was no difference in the ¹⁵N content of roots and shoots of clover plants after exposure to ¹⁵N. No labelled fixed nitrogen was detected in ryegrass plants growing with the clover plants for a period of 129 days. There was therefore no evidence of rapid direct transfer (excretion) of fixed nitrogen from clover to ryegrass.     

小麦根系形态数量性状的时空分布及其与土壤养分的关系研究

为明确小麦根系时空分布及其与土壤有效养分含量之间的相互关系,于2020—2021年进行大田试验,采用裂区设计,主处理为品种,分别选用大穗品种周麦30和多穗品种周麦32,副处理为种植密度,设置1.2×10⁶、2.4×10⁶、3.6×10⁶苗·hm^-2 3个密度。使用长方体铁盒(20 cm×5 cm×20 cm)在麦行上、行距1/4处、行距1/2处分别取0～20 cm和20～40 cm土层的样品。分析冬前期、返青期、拔节期、开花期、灌浆期、成熟期不同位点小麦根系形态数量性状(根长密度、平均根直径、根体积、根总表面积)及土壤碱解氮、有效磷和速效钾含量。结果表明,随着生育时期的推进,根总表面积、根长密度、根体积表现为先升高后降低的单峰曲线变化趋势;0～20 cm土层平均根直径呈“W”形曲线变化趋势,20～40 cm土层平均根直径呈“V”形曲线变化趋势。小麦根系垂直分布状况表现为：0～20 cm土层中根总表面积、根长密度、根体积均显著高于20～40 cm土层;20～40 cm土层平均根直径高于0～20 cm土...     

强度侵蚀山地不同治理措施对植被生长的影响及其生态效益分析

在福建省长汀河田强度侵蚀山地,采用固定标准样地定位研究和临时性调查相结合的方法,探讨了3种不同治理措施对强度侵蚀山地植被生长及生态效益方面的影响,结果表明：治理5年后,植被覆盖度明显提高,增长次序依次为草灌乔混交〉补植乔灌〉老头松改造〉对照;林木及草被生长加快,治理区植物种类呈明显增加趋势,草灌乔混交区植物种类最为丰富,达13科16属20种;土壤侵蚀率下降21．92％-32．14％,有机质含量提高3．76～4．48g／kg;治理区土壤侵蚀模数与对照区相比降幅达86％～91％;区域小气候等生态因子得到明显改善。这说明通过治理,能较好地促进强度侵蚀山地的植被生长,改善侵蚀区生态环境,而采用草灌乔混交措施的治理效果最好。     

不同耕作方式下水分管理对水稻氮素吸收利用的影响?

2008年早季和晚季,以桂旱1号和金优253为试验材料,盆栽条件下利用15N示踪技术研究了湿润灌溉、交替灌溉、水层灌溉3种水分管理模式下和免耕、常耕2种土壤耕作方式下水稻氮素与吸收利用的差异。结果表明：（1）湿润灌溉栽培降低了2种耕作方式水稻的氮肥吸收量,其中对基肥和分蘖肥吸收量的降低达显著水平;（2）湿润灌溉栽培时施入稻田中的氮肥被当季水稻吸收利用的比率下降,在土壤中的残留比率增加;（3）常耕条件下,湿润灌溉水稻氮素吸收总量明显低于水层灌溉和交替灌溉水稻,但免耕条件下湿润灌溉对水稻氮素吸收总量的影响比较小;（4）湿润灌溉时水稻产量和氮素的生产效率下降。     

滴灌减氮对植烟土壤无机氮变化及烟株氮积累的影响

为明确滴灌施肥条件下减量施氮对土壤无机氮变化特征、烟株氮积累规律的影响,于2016年在登封进行了田间试验,试验共设置5个处理:T0:不施氮肥;T1:常规施肥;T2:减氮15%;T3:减氮30%;T4:减氮45%。分析了0~20、20~40、40~60 cm土层无机氮含量及烟株氮积累量变化,并对0~20 cm土层无机氮含量拟合曲线及烟株氮积累拟合曲线特征值进行分析。结果表明,滴灌施肥能够显著提高栽后40、50 d时0~20 cm土层无机氮含量,显著降低栽后50 d时40~60 cm土层无机氮含量;减氮15%~30%对烟叶产量、生育期内烟株氮素积累量均无显著影响,减氮45%烟叶产量、烟株氮积累量、烟叶氮积累量分别显著下降11.52%、10.53%、10.50%;氮肥农学效率(NAE)、氮肥偏生产力(NPFP)均以T4处理最高,且随施氮量增加逐渐下降,氮肥表观利用率(ARE)以T3处理最高,氮收获指数(NHI)、氮肥生理利用率(NPE)与施氮量间无明显关系。减施氮肥土壤无机氮下降持续时间及烟株氮素快速增长时间会延长,无机氮最大下降速率及烟株最大氮积累速率降低,不利于烟株氮素快速积累。因此,综合考虑认为,在该地区条件下,滴灌施肥减氮15%~30%有利于氮肥高效应用。     

Nutrient utilization by pine seedlings and soil microbes in oligotrophic pine barrens forest soils subjected to prescribed fire treatment

The purpose of this greenhouse experiment was to examine the short-term effects of competition between pine seedlings and the soil microbial biomass in sandy oligotrophic pine barrens upland forest soils subjected to varying levels of prescribed fire severity. Pine seedling growth performance, microbial biomass nitrogen, extractable soil nutrients and leaching loss from the soil were determined, throughout a single growing season following fire treatment. Replicate soil cores exposed to three levels of fire severity were maintained in a greenhouse with or without a pine seedling. Throughout the following growing season replicate cores from each treatment were harvested and analyzed monthly. The data allowed testing for two main effects: soil fire treatment and tree presence/absence. In no instance was a significant fire treatment X tree presence/absence interaction found. Our results indicate that biological activity strongly influences soil conditions. Reduced microbial activity resulted from the interaction of soil microbial biomass and an individual pine seedling. Increased plant growth performance correlates with reduced soil mineral nitrogen concentration and decreased pH. At the levels of fire severity utilized in this experiment immobilization due to biological uptake and abiotic soil fixation prevented significant leaching losses above that of unburned control samples. In the oligotrophic, pine barrens soils, nitrogen and phosphorus mineralized by fire are largely conserved by biological processes. These results also suggest that plant growth is subject to limitation by phosphorus availability in these soils.     

Evaluation of Pine Bark or Pine Bark with Goat Manure or Sewage Sludge Cocomposts As Growing Media for Vegetable Seedlings

The suitability as growing media of composts made from pine bark or pine bark cocomposted with goat manure or sewage sludge and either inoculated or not inoculated with effective microorganisms, was evaluated under greenhouse conditions with and without fertilization using cabbage as the test crop. The treatments were replicated three times and arranged in a randomized complete block design in a fibre glass covered greenhouse. Cabbage seedlings were grown in cavity trays for five weeks, after which plants were harvested and fresh and dry weights determined. Samples were also analyzed for N, P, K and selected heavy metal concentrations. Results revealed that pine bark-goat manure cocomposts supported good seedling growth and could thus be good substitutes for pine bark alone as a growing medium where goat manure or similar manures are available. The results also showed that despite the superior nutritional value of these alternative growing media, nutrient supplementation may still be necessary where seedlings are kept in the nursery for extended periods due to nutrient exhaustion through plant uptake and leaching. Pine bark-sewage sludge compost also had positive effects on seedling growth but could only be recommended as a growing medium for nonfood plants because its composting did not reach the thermophillic temperatures necessary for adequate pathogen kill. Inoculation with effective microorganisms improved seedling growth in sewage sludge and goat manure based composts but the mechanisms involved remain to be established.