近红外技术快速测定肉鸡粪便主要肥料成分含量的研究

该文探讨了利用近红外光谱分析技术(NIRS)快速测定肉鸡粪便主要肥料成分含量的可行性。在饲养试验过程中采集了肉鸡粪便样品183个，利用常规实验室分析方法测定了其中的总氮(TN)、总磷(TP)、总钾(TK)、铵态氮(AN)、有效磷(EP)含量，利用近红外光谱仪取得了样品在1421.5～2572.2 nm波段的光谱，并使用偏最小二乘法(PLS)结合交互验证(CV)和留一检验法(LOO)建立了肉鸡粪便肥料成分的近红外光谱定标模型，同时利用该模型对20个样品的总氮、总磷、总钾、铵态氮、有效磷的含量进行预测，得出的5种主要肥料成分的预测值和真实值(实验室经典化学分析方法测定值)之间具有显著的相关性，其相关系数分别为0.9574，0.9590，0.9870，0.9572和0.9650。预测标准差分别为0.0014，0.0012，0.0012，2.3041×10^-4和0.3814。结果表明，利用近红外光谱法对肉鸡粪便风干样品的主要肥料成分进行快速测定是可行的。     

基于物理指标快速预测猪粪尿肥料成分含量的试验研究

该试验旨在研究家畜粪便的物理指标与其肥料成分含量的关系，用来预测猪粪便肥料成分含量。通过对鲜粪便的理化指标测定的试验数据进行统计分析后提出，电导仪和密度计两种实验室常用仪器可实现对猪粪便中肥料成分氮、磷、钾含量的预测：用电导率这一物理指标可准确预测猪粪、猪尿和粪尿混合物中铵态氮的含量，同时可准确预测猪粪、猪尿和粪尿混合物中钾的含量；用密度这一物理指标可较准确地预测猪粪、猪尿和粪尿混合物中总氮的含量，同时可较准确地预测猪粪尿混合物中磷的含量。分析中发现猪尿中总氮和铵态氮比例基本稳定，由此推想用电导率来预测猪     

烤烟成熟鲜烟叶生化组分高光谱估算方法筛选

为实现实时无损快速预测鲜烟叶的品质生化组分、筛选估算生化组分最佳的方法，使用ASD Fieldspec FR2500对烤烟成熟鲜烟叶进行了反射率、透射率光谱测定和常规生化组分分析。对可见近红外波段(350～1650 nm)单波段光谱和选用已有100种光谱指数共两类光谱参量进行了与生化组分之间线性函数、幂函数、指数函数共3种形式相关分析和基于决定系数的筛选。结果表明，对于叶绿素a、叶绿素b、类胡萝卜素、钾估算方法分别是Gitelson and Merzlyak2(GM₂) (R²=0.81)、光化学指数2(PRI₂) (R²=0.80)、Gitelson and Merzlyak2(GM₂) (R²=0.83)、1420 nm吸收峰开始位置(λs₁₄₂₀) (R²=0.67)的线性拟合最优。对于总糖、比叶重、氮、烟碱最优方法分别是在532 nm反射率一阶微分线性拟合(R²=0.54)、在1423 nm透射率线性拟合(R²=0.45)、在666 nm反射率倒数对数一阶微分的幂函数拟合(R²=0.44)，在1135 nm反射率倒数对数二阶微分的线性拟合(R²=0.20)。通过筛选的光谱方法可以评估烟叶的品质状况。     

长江中下游甘薯氮磷钾肥施用效果与区域土壤养分丰缺指标研究

根据2009—2014年在长江中下游薯区实施的68个氮、磷、钾肥料用量田间试验结果，建立了基于养分丰缺指标法——肥料效应函数的甘薯氮、磷、钾施肥指标体系。结果表明：施用氮肥、磷肥、钾肥均对甘薯具有极显著的增产效果(P<0.01)；植薯土壤水解性氮含量的“高”、“低”指标分别为170 mg/kg和100 mg/kg，有效磷含量的临界指标为17 mg/kg，土壤速效钾含量“高”、“低”的指标分别为110 mg/kg和30 mg/kg；高产田块甘薯的氮、磷、钾肥最佳经济推荐施用量分别为N 125 kg/hm²、P₂O₅160 kg/hm²和K₂O 182 kg/hm²，中低产田块的氮、磷、钾肥最佳经济推荐施用量分别为N 155 kg/hm²、P₂O₅120 kg/hm²和K₂O 220 kg/hm²。     

基于高光谱的鲁西北平原土壤有效磷含量快速检测研究

土壤有效磷含量是农田土地评价的指标, 也是农作物施肥的基本指标, 快速准确测量土壤有效磷含量是土壤信息化管理和资源评价的前提条件。高光谱技术的发展为快速有效监测土壤有效磷含量提供了新的途径。本文对466个样点的土壤有机质、碱解氮、有效磷和速效钾含量进行了测定, 通过聚类分析和方差分析选取48个有机质、碱解氮、速效钾含量相近而有效磷差别较大的样点作为研究样点, 采用美国ASD Fieldspec3光谱仪, 对不同有效磷含量的土壤样本高光谱反射率进行测量, 并对反射率进行倒数、对数、平方根、对数的倒数、倒数的对数的变换及其各自相应的一阶导数变换, 将每个土样测定的有效磷含量值与350~ 2 500 nm光谱范围的反射率数据及反射率的9种变换形式逐一逐波段地进行单相关分析, 筛选出对有效磷敏感的光谱波段。将所选取的显著相关波段反射率或变换形式作为自变量, 与土壤中有效磷含量进行一元线性回归方程拟合, 对所建立的回归方程进行优选和检验。研究得出: 采用相关分析方法得出土壤有效磷含量的敏感波段为711 nm, 利用一元线性回归方法, 基于该波段的估算模型为最佳估算有效磷含量模型, 该模型的拟合优度R²达0.822 1, 验证决定系数R²达0.959 1。由此说明, 利用单个敏感波段建立土壤有效磷的反演模型, 可作为快速测量土壤有效磷含量的一种简单而可靠的方法。     

离子交换树脂膜测定肥料养分在土壤中的变化

在25℃恒温培养条件下，采用离子交换树脂膜(IERM)连续提取法研究了不同肥料(尿素、氯化钾、磷酸二氢钙、缓释复合肥)养分(氮、磷、钾)在土壤中的变化。结果表明，几种肥料养分释放速率各异，缓释复合肥氮、磷养分释放在前期(28 d)释放较慢。用该方法提取肥料养分(N、P、K)在土壤中的释放累积量随时间的增加而增大，用Elovich、双常数、一级扩散、抛物线扩散4种动力学方程来描述二者的关系，拟合度都达到了极显著水平(r=0.863^**～0.999^**)。用该法测定肥料在土壤中释放养分的变化特性与用其测定的土壤本身养分的变化特性相似。从而提出了离子交换树脂膜法作为一种评价肥料养分在土壤中的变化特性的较理想方法的可能性。     

封育对蒿类荒漠草地土壤氮素含量及其组分特征的影响

为探讨蒿类荒漠草地土壤氮素含量及其组分特征,采用成对试验设计,研究封育对天山北坡不同区域蒿类荒漠草地土壤全氮、碱解氮、硝态氮和铵态氮含量的影响。结果表明:(1)封育后蒿类荒漠草地0—50 cm土层土壤氮密度(0.59~0.79 kg/m²)、土壤全氮含量(0.81~1.50 g/kg)、土壤碱解氮含量(19.44~67.49 mg/kg)变化不显著(p＞0.05)。(2)封育对蒿类荒漠草地土壤硝态氮含量(6.41~21.26 mg/kg)、铵态氮含量(0.26~2.53 mg/kg)的影响因区域差异而有所不同。封育后巩留、呼图壁样地0—50 cm土层硝态氮含量依次显著降低24.61%,47.25%(p＜0.01),而奇台样地则显著增加20.95%(p＜0.05);封育后玛纳斯样地0—50 cm土层铵态氮含量显著增加27.98%(p＜0.05),而巩留、博乐、呼图壁样地则降低不显著(p＞0.05)。(3)蒿类荒漠草地土壤硝态氮、铵态氮含量依次占全氮量的0.27%~3.01%,0.02%~0.42%,且随土壤全氮的增加,有机氮占比增加,而无机氮、硝态氮和铵态氮占比降低。(4)相关分析表明,土壤全氮、碱解氮、硝态氮、铵态氮与有机碳、全磷呈正相关,与土壤容重、pH、电导率呈负相关,铵态氮与土壤含水量呈正相关,与速效磷呈负相关。偏冗余分析表明,土壤理化因子对土壤氮素影响的主要因子为土壤有机碳和土壤含水量,解释率依次为32.60%,17.90%。研究结果为揭示封育过程中蒿类荒漠草地土壤恢复及养分管理提供科学数据支撑。     

氮、磷、钾配施对胡麻产量的影响及推荐施肥量研究

为了揭示氮、磷、钾肥配施对胡麻生长的影响,采用“3414”不完全正交回归设计,研究了3种施肥梯度下胡麻经济性状、产量、增产率、肥料贡献率和产投比等的变化,并进行胡麻产量肥效模型函数拟合。结果表明:低氮、磷、钾和中氮、磷、钾施肥水平有利于提高胡麻经济性状指标;施氮、磷、钾处理下胡麻产量较不施氮、磷、钾肥处理提高了4.95%～24.07%,胡麻产量随着施肥量的增长呈现出先增高后降低的趋势,当氮(N)、磷(P2O5)、钾(K2O)分别为75、67.5、72 kg/hm²时胡麻产量最高;钾肥对胡麻产量的贡献大于氮肥和磷肥,高磷具有明显的减产效应;通过肥料效应函数拟合分析,本试验条件下推荐最高施肥量为:N 69.1 kg/hm²,P2O5 51.5 kg/hm²,K2O 63.4 kg/hm²,最佳施肥量为:N 39.6 kg/hm²,P2O5 26.5 kg/hm²,K2O 25.7 kg/hm²。     

高阳县农田土壤速效养分空间变异特征研究

土壤养分空间变异的研究对指导测土配方施肥具有重要意义。为了便于土壤养分的管理, 以河北省保定市高阳县为例, 应用地统计学和GIS相结合的方法, 研究了农田土壤速效氮、磷、钾含量的空间变异特征。结果表明: 土壤速效氮、磷、钾的含量范围分别为10.50~210.00 mg·kg^-1、1.02~197.75 mg·kg^-1和14.51~376.18 mg·kg^-1, 平均值分别为76.32 mg·kg^-1、22.28 mg·kg^-1和128.34 mg·kg^-1, 变异系数范围为36.11%~79.71%, 属于中等强度变异。速效氮、磷、钾的C0/(C0+C)值均介于25%~75%, 表现出中等强度的空间自相关, 空间变异是结构因素和随机因素共同作用的结果, 空间相关距离分别为43.96 km、1.05 km和51.94 km。通过插值误差的比较得出最优拟合模型, 速效氮、磷、钾最好的理论模型分别为球状模型、指数模型和球状模型, 趋势效应参数宜选取0阶。然后用普通克里格方法绘制了土壤速效氮、磷、钾的空间分布图, 速效氮含量绝大部分属低等水平, 无明显分布特征, 速效磷空间分布呈条带状, 速效钾空间分布呈条带状和岛状分布相结合的特点。     

陕北石油污染对土壤理化性质的影响

为了研究石油污染对土壤理化性质的影响,对安塞县8个类型油井井场周围土壤中的石油烃含量和理化性质进行分析测定。结果表明,井场周围土壤石油烃含量变化范围为0.08~71.49 g/kg,其中井场外0~5 m区域和5~20 m区域内土壤污染严重。石油污染导致土壤含水率、pH值、硝态氮、速效磷、全钾和速效钾含量显著降低,容重、有机质和铵态氮含量显著升高,全氮和全磷含量无显著变化;石油污染土壤中的石油烃含量与含水率、容重、有机质、铵态氮、速效磷和速效钾均呈极显著相关,与pH值和全钾呈显著相关,与全氮、硝态氮和全磷无显著相关关系。     

N2O and CH4 fluxes from a volcanic grassland soil in Nasu,Japan: Comparison between manure plus fertilizer plot and fertilizer-only plot

Abstract

We examined the effects of manure + fertilizer application and fertilizer-only application on nitrous oxide (N₂O) and methane (CH₄) fluxes from a volcanic grassland soil in Nasu, Japan. In the manure + fertilizer applied plot (manure plot), the sum of N mineralized from the manure and N applied as ammonium sulfate was adjusted to 210 kg N ha^?1 year^?1. In the fertilizer-only applied plot (fertilizer plot), 210 kg N ha^?1 year^?1 was applied as ammonium sulfate. The manure was applied to the manure plot in November and the fertilizer was applied to both plots in March, May, July and September. From November 2004 to November 2006, we regularly measured N₂O and CH₄ fluxes using closed chambers. Annual N₂O emissions from the manure and fertilizer plots ranged from 7.0 to 11.0 and from 4.7 to 9.1 kg N ha^?1, respectively. Annual N₂O emissions were greater from the manure plot than from the fertilizer plot (P < 0.05). This difference could be attributed to N₂O emissions following manure application. N₂O fluxes were correlated with soil temperature (R = 0.70, P < 0.001), NH⁺ ₄ concentration in the soil (R = 0.67, P < 0.001), soil pH (R = –0.46, P < 0.001) and NO^? ₃ concentration in the soil (R = 0.40, P < 0.001). When included in the multiple regression model (R = 0.72, P < 0.001), however, the following variables were significant: NH⁺ ₄ concentration in the soil (β = 0.52, P < 0.001), soil temperature (β = 0.36, P < 0.001) and soil moisture content (β = 0.26, P < 0.001). Annual CH₄ emissions from the manure and fertilizer plots ranged from –0.74 to –0.16 and from –0.84 to –0.52 kg C ha^?1, respectively. No significant difference was observed in annual CH₄ emissions between the plots. During the third grass-growing period from July to September, however, cumulative CH₄ emissions were greater from the manure plot than from the fertilizer plot (P < 0.05). CH₄ fluxes were correlated with NH⁺ ₄ concentration in the soil (R = 0.21, P < 0.05) and soil moisture content (R = 0.20, P < 0.05). When included in the multiple regression model (R = 0.29, P < 0.05), both NH⁺ ₄ concentration in the soil (β = 0.20, P < 0.05) and soil moisture content (β = 0.20, P < 0.05) were significant.     

Evaluation of biological and chemical nitrogen indices for predicting nitrogen-supplying capacity of paddy soils in the Taihu Lake region,China

Simple and rapid chemical indices of soil nitrogen (N)-supplying capacity are necessary for fertilizer recommendations. In this study, pot experiment involving rice, anaerobic incubation, and chemical analysis were conducted for paddy soils collected from nine locations in the Taihu Lake region of China. The paddy soils showed large variability in N-supplying capacity as indicated by the total N uptake (TNU) by rice plants in a pot experiment, which ranged from 639.7 to 1,046.2 mg N pot⁻¹ at maturity stage, representing 5.8% of the total soil N on average. Anaerobic incubation for 3, 14, 28, and 112 days all resulted in a significant (P < 0.01) correlation between cumulative mineral NH₄⁺-N and TNU, but generally better correlations were obtained with increasing incubation time. Soil organic C, total soil N, microbial C, and ultraviolet absorbance of NaHCO₃ extract at 205 and 260 nm revealed no clear relationship with TNU or cumulative mineral NH₄⁺-N. Soil C/N ratio, acid KMnO₄-NH₄⁺-N, alkaline KMnO₄-NH₄⁺-N, phosphate–borate buffer extractable NH₄⁺-N (PB-NH₄⁺-N), phosphate–borate buffer hydrolyzable NH₄⁺-N (PB_HYDR-NH₄⁺-N) and hot KCl extractable NH₄⁺-N (H_KCl−NH₄⁺-N) were all significantly (P < 0.05) related to TNU and cumulative mineral NH₄⁺-N of long-term incubation (>28 days). However, the best chemical index of soil N-supplying capacity was the soil C/N ratio, which showed the highest correlation with TNU at maturity stage (R = −0.929, P < 0.001) and cumulative mineral NH₄⁺-N (R = −0.971, P < 0.001). Acid KMnO₄-NH₄⁺-N plus native soil NH₄⁺-N produced similar, but slightly worse predictions of soil N-supplying capacity than the soil C/N ratio.     

Zusammensetzung und Eigenschaften von Sickerwasser aus Stallmiststapeln

Composition and properties of leachates from farmyard manure heaps Besides some rheological characteristics, the N_total, NH₄⁺-N, NO₃^? -N, P, K⁺, dry matter and ash content, as well as chemical oxygen demand and conductivity of farmyard manure leachates were examined. The K⁺ concentration was highest with an average of 5921 mg l^?1, followed by N_total (1139 mg l^?1, 66% of it as NH₄⁺-N and 4% NO₃^?-N) and P (334 mg l^?1). All parameters were highest in leachates of fresh manure and lowest at the end of a 6 months storage period. During the storage, the P concentration in leachates showed a decrease of 67.7%, followed by a decrease in N_t (-57.3%) and K⁺ (-24.0%). In leachates from a manure with an relatively high initial N_t content of 0.51% and a low C:N ratio of 16.8 the N_t concentration was 0.5–1 times higher than that of a manure with 0.44% N_t and a C:N ratio of 19.9. The viscosity and the thixotropy of leachates were both relatively high at the beginning of the manure's storage period, which led to a strongly developed blocking of porous systems. These properties that contribute to explain the high retention rate of nutrients in the top soil layer at manure storage sites, decreased with an increase in storage time.     

Influence of green manuring with Sesbania rostrata and Aeschynomene afraspera or urea on dynamics and uptake of nutrients by wetland rice

Nutrient concentrations in the soil and crop uptake from incorporated green manure and urea in flooded rice was studied in field experiments. Release of plant-available nitrogen (NH₄ ⁺-N) from green manure was slightly delayed compared with that from prilled urea (PU) because Sesbania rostrata L. and Aeschynomene afraspera L. released the N gradually after their decomposition, whereas N became available immediately after PU application. Exchangeable NH₄ ⁺-N concentration in soil peaked at 163 mg kg^–1 in the transplanted rice (TPR) and 198 mg kg^—1 in broadcast-seeded rice (BSR) at 0 and 1 week after PU application. Broadcast-seeded rice depleted NH₄ ⁺-N faster than did TPR because of the crop‘s vigorous growth in the former during the early stage. Soil solution NH₄ ⁺-N followed a similar trend to that of soil NH₄ ⁺-N. Incorporation of S. rostrata and A. afraspera increased the concentration of P, K⁺, Fe²⁺ and Mn²⁺ in soil solution more than did the application of PU. However, zinc concentration decreased in all treatments. Both PU and green manure increased the N status of the rice plants and enhanced the uptake of P, K, Fe, Mn and Zn by the rice crop. This suggests that application of green manures improves the uptake of these nutrients by the crop. The highest apparent N recovery was obtained with PU followed by green manure. Received: 11 November 1996     

Nutrient dynamics,dehydrogenase activity,and response of the rice plant to fertilization sources in an acid lateritic soil

Abstract

Rice variety IR 36, grown under flooding, was studied in 1998 to determine the effects of fly ash, organic, and inorganic fertilizers on changes in pH and organic carbon, release of nutrients (NH₄ ⁺-N, Bray's P, and NH₄OAc K), and dehydrogenase activity in an acid lateritic soil at 15-day intervals. Application of fly ash at 10?t?ha^?1 alone did not improve the availability of NH₄ ⁺-N, or P, as well as the rice grain yield. Availability of NH₄ ⁺-N (35.3–36.9?mg?kg^?1), and P (12.3–14.6?mg?kg^?1) at 15 days after transplanting, and rice grain yields (48.0–51.7?g per pot) were similar under the various fertilization sources such as inorganic fertilizer alone, inorganic fertilizer?+?fly ash or inorganic fertilizer?+?green manure?+?fly ash. Mean dehydrogenase activity was the highest (8.47?µg triphenyl formazon g^?1 24?h^?1) under the mixed fertilization treatments with green manure. At the end of the cropping season (75 days after transplanting), pH, organic carbon, and dehydrogenase activity were higher under the mixed fertilization treatments involving green manure by 3, 15 and 154%, respectively, compared with the inorganic fertilizer alone.     

Effect of Adding Flue Gas Desulphurization Gypsum on the Transformation and Fate of Nitrogen during Composting

The objective of this study was to investigate the effect of adding flue gas desulphurization gypsum (FGDG) on the transformation and fate of nitrogen during co-composting of dairy manure and pressmud of a sugar refinery. The ammonia absorption of FGDG was investigated. The changes in compost temperature, pH, electrical conductivity (EC), moisture, organic matter, the C/N ratio, Kjeldahl N, NH₄⁺-N, NO₂^?-N, NO₃^?-N were assessed. The addition of FGDG did not significantly affect compost temperature, pH, EC, moisture, and organic matter degradation. However, the addition of FGDG significantly increased the NH₄⁺-N content in the compost during the thermophilic phase, and the NH₄⁺-N maximal content in the compost with FGDG (CP+G) was 59.9% more than that in the compost without FGDG (CP–G). FGDG was thought to create the formation of (NH₄)₂SO₄ and the cation exchange between NH₄⁺ and Ca²⁺. The NO₂^?-N content in the CP+G peaked on day 15, and was not observed in the CP–G. In the final compost products, the NO₃^?-N concentration in the CP–G was more than that in the CP+G, which was 1451 (CP–G) and 1109 mg·kg^?1 (CP+G) dry material. This might be due to the NO₂^? accumulation in the CP+G, which accelerated N loss in the form of N₂O. There is a strong correlation between N₂O emission and NO₂^?-N accumulation in the composting process. Compared with the original N content in the compost mixture, the N loss in CP–G and CP+G were 15.0 and 10.8%, respectively. These results revealed that NH₄⁺-N conservation effect was improved during the thermophilic phase and the total N loss was mitigated by adding FGDG into composting materials. FGDG could be utilized as a potential amendment to conserve nitrogen during composting.     

Toxicity Evaluation of Weathered Coal Fly Ash–Amended Manure Compost

The general use of manure compost is limited by its residualtoxicity, and hence a study was performed to evaluate the use ofweathered coal fly ash (lagoon ash) to alleviate the toxicity ofmanure compost. Mature and immature manure compost were amendedwith lagoon ash at 0, 5, 10 and 20% (w/w dry weight basis), andtheir phyto-toxicity was evaluated by germination and root lengthgrowth of lettuce seed. The immature manure compost hadsignificantly higher contents of NH₄-N, PO₄-P, andacid- and water-extractable Cu and Zn contents than those of mature manure compost. Ash amendment caused asignificant increase in electrical conductivity (EC), but adecrease in NH₄-N, PO₄-P, and DTPA-, CaCl₂- andwater-extractable Cd, Cu, Pb and Zn contents of both manurecompost. Addition of lagoon ash at a rate of 5% for immaturemanure compost and 10% for mature manure compost resulted in ahigher seed germination rate and root length growth. Thegermination index demonstrated significant negative correlationswith EC, NH₄-N and DTPA extractable Cd, Cu, Pb and Zncontents. The present study supports the use of lagoon ash foramending manure compost to reduce the availability of traceelements and NH₄-N.     

有机肥无机肥配施对稻田氨挥发和水稻产量的影响

在南方红壤区双季稻田进行田间试验,研究等氮、磷、钾量条件下,有机无机肥配施对稻田氨挥发及水稻产量的影响。结果表明,有机无机肥配合施用能显著地降低稻田氨挥发,减少氮素损失,提高氮肥利用率。单施化肥(尿素),其氨挥发损失达37.8%,而单施有机肥和有机无机肥各半配合施用,氨挥发损失分别为0.7％-1.0％和7.2％-18.2％。田间氨挥发持续的时间,早稻约在施肥后20d,晚稻为9-10d。虽然有机无机肥各半配合施用的水稻产量与单施化肥的相近,均比对照提高约70％,但前者的氮损失少,其氮肥利用率为34.9％,高于化肥处理(33.2％)和有机肥处理(28.0%)。有机无机肥配合施用对提高水稻产量和降低氮肥环境负效应的综合效应最佳。     

不同来源有机物料对菜用蚕豆生长和品质及根际土壤性状的影响

通过盆栽试验,分析了不同来源有机物料(鸡粪、牛粪、菇渣)对菜用蚕豆生长和品质、根际土化学和生物学性状的影响。结果表明：(1)3种有机物料对蚕豆分枝数、荚干重、籽粒干重、大粒重、大粒蚕豆占比、籽粒淀粉含量均有积极作用,其中牛粪和菇渣能显著(P<0.05)提高大粒蚕豆占比,鸡粪能显著(P<0.05)提高二粒荚和三粒荚的占比,并且对籽粒淀粉含量的提升效果最为明显(比对照增加69.1%);(2)3种有机物料增加了根际土中细菌、真菌数量,显著(P<0.05)提高了根际土中性转化酶、脲酶、酸性磷酸酶、多酚氧化酶活性(除牛粪使中性转化酶活性提高不显著外),其中鸡粪对细菌数量、中性转化酶活性、脲酶活性的提高程度均最大;(3)鸡粪能显著(P<0.05)增加根际土有机碳、全氮、NH₄⁺-N含量,牛粪、鸡粪能显著(P<0.05)提高土壤p H。大粒蚕豆占比与土壤酸性磷酸酶活性、有效磷含量呈显著正相关。蚕豆淀粉含量与细菌数量、中性转化酶活性、有机碳、全氮、NH₄⁺-N含量呈显著正相关,这说明有...     

铁和不同形态氮素对玉米植株吸收矿质元素及其在体内分布的影响——Ⅰ.对氮、磷、钾、钙、镁等营养元素的影响

用营养液培养方法研究了铁和两种形态氮素(NO₃^--N和NH₄⁺-N)对玉米植株吸收氮、磷、钾等大量元素和钙、镁等中量元素及其在体内分布的影响。结果表明:与NO₃^--N相比,供应NH₄⁺-N促进了玉米对氮的吸收,在缺铁条件下,降低了对磷、钾、钙及镁的吸收。铁和NH₄⁺-N都显著提高了玉米植株各器官中氮的含量。与NH₄⁺-N处理相比,NO₃^--N处理的新叶中磷含量显著增加,但铁的供应对植物体内磷的含量无显著影响。使用NO₃^--N显著提高了玉米新叶和老叶中钾的含量,根和茎中钾的含量无明显影响。铁的供应降低了新叶和老叶中钾的含量。供铁时,NH₄⁺-N处理的玉米新叶中钙和镁的含量显著低于NO₃^--N处理,而在缺铁时则无显著差异。