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1.
ABSTRACT

A long-term field experiment was performed to assess the effects of fertilization regimes on greenhouse gas emissions, soil properties, soil denitrifies, and maize (Zea mays) grain yield on Mollisols of Northeastern China. Chemical nitrogen (N), phosphorus (P), and potassium (K) fertilizers plus pig manure (MNPK) treatment significantly increased soil N2O emissions by 29.9–226.4% and global warming potential (GWP) by 29.8–230.7% compared to unfertilized control (CK), chemical N fertilizer only (N), chemical N, P, and K fertilizers (NPK) and chemical N, P, and K fertilizers plus corn straw (SNPK) treatments. However, the MNPK treatment yielded similar greenhouse gas intensity (GHGI) as compared with other treatments, mainly due to higher maize grain yield. There were also higher gene copy numbers of nirK, nirS, and nosZ in topsoil (0–20 cm depth) under MNPK treatment. Automatic linear modeling analysis indicated that main factors influencing soil N2O emissions were soil organic carbon (SOC), NO3? content, and nirK gene abundance. Although the application of chemical fertilizers plus organic manure increases N2O emissions due to higher N and C availability and nirK gene activity in the soil, this is still a promising fertilizer management due to its notable enhancement of maize grain yield and SOC content.  相似文献   

2.
[目的]探讨我国典型赤红壤区——广州市增城区耕层土壤有机质、全氮、有效磷和速效钾含量的空间变异规律,为赤红壤区耕层种植的平衡施肥、水土保持和环境保护提供依据。[方法]利用地统计学方法和地理信息系统技术。[结果]研究区耕层土壤有效磷的含量较高,速效钾的变异系数最大(107.78%),有机质的变异系数最小(32.51%),变异系数由大到小依次为:速效钾有效磷全氮有机质;有机质、全氮具有强烈的各向同性空间自相关性,有效磷与速效钾有着较明显的各向异性空间自相关性;有机质、全氮有着相似的空间分布规律,含量呈东南部高西北低的趋势,有效磷含量处于中上偏高水平,空间分布从北向南呈逐步增多趋势,速效钾空间分布相对比较复杂,各个养分级别都有一定量的分布,总体由北到南逐渐增多。[结论]在一定空间范围内,耕层土壤有机质、全氮、有效磷和速效钾具有不同强度的空间相关性,且选取合适的方向性半方差函数模型能更好地拟合其空间变异情况。  相似文献   

3.

Within-field variations in plant-available soil nitrogen (N) are likely to be affected by differences in soil characteristics. To study this, a 3- year field investigation was conducted during 1998-2000 on a 15 ha arable field in Sweden with considerable within-field soil texture variability. In 34 plots soil N uptake by crops, net nitrogen mineralization (Nm) during the growing season and soil mineral N in spring and shortly after harvest were determined. Beside these parameters, topography, soil organic matter content (SOM), clay content, pH(H 2 O) and grain yield were recorded. The variations in Nm were considerably large both within the field and between years. The within-field variation in Nm could partly be explained by the variation in SOM and clay content (adjusted coefficient of determination = 0.23, P <0.001). The pattern in Nm differed between years, partly because of seasonal variations in soil moisture. For these reasons, the pattern of Nm is difficult to predict without seasonal adjustments.  相似文献   

4.
Abstract

Laboratory and field experiments were conducted at the Regional Research Station of Kandi Area, Ballowal Saunkhri, Punjab, India, to determine the immediate influence of artificial topsoil removal (simulated erosion) on selected soil properties, maize (Zea mays) growth and yield, and restoration of crop productivity with nitrogen (N) fertilization. For the laboratory experiment, soil samples (0–15 cm) were obtained after removing 0, 6, 12, and 18 cm of a sandy loam topsoil from a cereal grain cropped field. In the field experiment, topsoil was removed at 0, 6, 12, and 18 cm in main plots, and six N treatments at rates of 0, 40, 80, 120, 160, and 200 kg N ha‐1 were applied in subplots. Topsoil removal greatly decreased mineralized N, N mineralization potential and rate constant, and increased time for half mineralization of N. Bulk density and penetration resistance increased as a result of topsoil removal and infiltration capacity of the soil decreased. Total profile water was more at the time of harvest than at sowing in the plots where topsoil was removed, but the water expense efficiency decreased. Both grain and straw yield of maize decreased substantially as a result of adverse effect of topsoil removal on plant height, mass and depth of root, length and girth of cob, and thousand grain weight. Nitrogen application improved maize growth and yield, but the crop responded to higher doses of N on eroded plots than the uneroded plots, and yields on eroded plots did not match to those obtained on uneroded plots at any level of N application. In conclusion, artificial surface soil erosion deteriorated soil properties governing maize productivity. More N was required where topsoil had been eroded, but N application alone did not restore crop yield to that level obtained from uneroded soil. Therefore, there is a need to look for and quantify other factors also to improve soil productivity.  相似文献   

5.
Within-field variability in wheat grain yield and its quality always exists in production fields and depends, among other factors, mainly on various soil properties related to nutrients and water availability. The aim of the research was to examine the relationships between selected soil properties such as texture; pH; content of the available phosphorus (P), potassium (K), magnesium (Mg), and organic carbon; and winter wheat grain yield and quality under rainfed conditions. Six crop fields with winter wheat (Triticum aestivum, L.) in three sites located in different regions of Poland were examined during two seasons. The grain yield was mainly determined by the soil texture, and the majority of the chemical soil properties did not have a significant effect on grain yield. The grain quality traits were determined by the examined soil properties to a smaller degree than grain yield. The relationships were not consistent across sites and years.  相似文献   

6.
Intercropping is of increasing interest in temperate-arable farming systems. The influence of nitrogen (N) fertilization and sowing ratio on concentrations and uptake of calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P) by oat and pea was assessed in three substitutive intercrops on a fertile soil in eastern Austria. N decreased Ca in oat grain and increased P in pea grain as well as Ca and Mg in oat residue and Mg and P in pea residue. Intercropping did not affect nutrient concentrations of oat grain, whereas a lower pea share in intercrops increased P in pea grain. In residue, Ca, K and Mg concentrations were higher in oat and Ca and K partly lower in pea with a lower share of each crop. The oat-dominated intercrops could partly achieve a slightly higher total grain nutrient yield than pure stands at no or low N; however, these benefits diminished with a higher pea share and N input. In comparison to pure stands, higher residue nutrient yields were obtained by intercropping in all sowing ratios and fertilization levels. Consequently, oat–pea intercropping can be a strategy for increasing the macronutrient yield of grain and especially of residue for ruminant feeding.  相似文献   

7.
Mountain region citrus production systems occupy large parts of the landscape prone to soil erosion in the Three‐Gorges Area of China. Several soil conservation measures, such as terracing hedgerows, are widely implemented in citrus orchards to control soil erosion. However, little is known about the effect of those measures on soil properties. The objective of this work was to analyse the changes of soil properties in citrus orchards subjected to different conservation measures. Experiments were conducted in four plots: control plot (SC, sloping orchard without conservation measures), sloping orchard with contour hedgerows (SCH), terraced orchard (TC) and terraced orchard with grass cover (TCG). Samples of soil surface from 0 to 15 cm were collected to analyse texture, bulk density (BD), aggregate stability, saturated hydraulic conductivity, soil organic matter (SOM) and soil nutrients. The spatial variability of those properties was also evaluated at slope and field scales. The results showed that the three conservation measures significantly increased saturated hydraulic conductivity, aggregate stability, SOM and available N, P, K, but decreased BD. The terracing with grass cover measures were the most effective in improving soil fertility among the three measures. The average SOM, available P, N, K in TCG were 0·27, 0·50, 1·74 and 1·72 and these rates are larger than for the in SC. Compared to SC, silt content was increased the SCH, while clay content was increased with TC and TCG. There was a downslope increase in clay content and total N but a decrease in gravels in the SC plot. However, that trend did not exist in the other plots. At the field scale, the soil aggregate stability and total nitrogen were significantly higher near the hedgerow under SCH, and the available N was significantly higher in the middle position under TC; the other soil properties had no significant trends based on the distance to hedgerow or stone bunds. Results of this study will contribute to a further understanding of the environmental influence of soil conservation measures. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

8.
ABSTRACT

Knowledge of spatial variability in soil properties is critical for effective nutrient management plan in crop production. Poor productivity of apple orchards in Indian Himalayan Region (IHR) is due to lack of information on the variability of soil properties important for enhancing productivity in the region. The study was conducted in apple orchards with the hypothesis that spatial variability of soil properties is high due to adoption of varied management and passive soil factors. The major objectives of the study were to assess the spatial variability of soil parameters, viz. soil pH, electrical conductivity, soil organic carbon along with plant available soil nitrogen (N), phosphorus (P), potassium (K), exchangeable calcium (Ca), and exchangeable magnesium (Mg) at a regional scale through geostatistical methods. Coefficient of variation (CV) indicated that the fertility parameters varied from medium to high in heterogeneity (CV > 20%). Available N was found critical/medium in 69.6% of soil samples and might be one of the limiting nutrients for crop growth, P and K were in high, and OC in very high range. Significant correlation was found between OC with N; pH with K, Ca and Mg and EC with OC, P and K. The semivariogram parameters indicated that the spatial distribution of soil fertility parameters were inconsistent and showed strong to weak degree of spatial dependence for all parameters. The study highlighted the importance of delineation of soil fertility management zones in the apple growing region as a guide for precise and site-specific nutrient.  相似文献   

9.
Accelerated soil erosion can impact upon agronomic productivity by reducing topsoil depth (TSD), decreasing plant available water capacity and creating nutrient imbalance in soil and within plant. Research information on soil‐specific cause – effect relationship is needed to develop management strategies for restoring productivity of eroded soils. Therefore, two field experiments were established on Alfisols in central Ohio to quantify erosion‐induced changes in soil properties and assess their effects on corn growth and yield. Experiment 1 involved studying the effects of past erosion on soil properties and corn yield on field runoff plots where soil was severely eroded and comparing it with that on adjacent slightly eroded soil. In addition, soil properties and corn grain yield in runoff plots were compared on side‐slopes with that on toe‐slopes or depositional sites. Experiment 2 involved relating corn growth and yield to topsoil depth on a sloping land. With recommended rates of fertilizer application, corn grain yield did not differ among erosional phases. Fertilizer application masked the adverse effects of erosion on corn yield. Corn grain yield on depositional sites was about 50 per cent more than that on side‐slope position. Corn plants on the side‐slope positions exhibited symptoms of nutrient deficiency, and the ear leaves contained significantly lower concentrations of P and Mg and higher concentrations of Mn and K than those grown on depositional sites. Corn grain yield in experiment 2 was positively correlated with the TSD. Soil in the depositional site contained significantly more sand and silt and less clay than that on the side‐slope position. There were also differences in soil properties among erosional phases. The soil organic carbon (SOC) content was 19\7 g kg−1 in slightly eroded compared with 15\1 g kg−1 in severely eroded sites. Aggregate stability and the mean weight diameter (MWD) were also significantly more in slightly eroded than severely eroded soils. Adverse effects of severe erosion on soil quality were related to reduction in soil water retention, and decrease in soil concentration of N and P, and increase in those of K, Ca and Mg. Severe erosion increased leaf nutrient contents of K, Mn and Fe and decreased those of Ca and Mg. Corn grain yield was positively correlated with aggregation, silt and soil N contents. It was also negatively correlated with leaf content of Fe. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

10.
Within-field soil variability has often been reported in Japanese paddy fields. In one of such fields, we examined the relationships of spatial variations among different forms of soil nutrients and their direct influence on rice growth. Samples of surface soils collected from 100 plots (5 x 10 m) in the field were analyzed for the contents of N, P, and K as well as for the total C and clay contents. The values of the coefficient of variation (CV) for the soil properties were relatively high, ranging from 7% (total K) to 33% (inorganic N). More than 60% of the variation was spatially dependent, with ranges of less than 30 m for the contents of inorganic N and clay, 30-40 m for the contents of N (mineralizable and total), P (water-soluble, available, and total), and total C, and more than 60 m for the content of K (water-soluble, exchangeable, and nonexchangeable). These properties were grouped into two types; those significantly correlated either with the total C content (contents of mineralizable N, total N, all P forms, water-soluble K, exchangeable K, and 0.01 M HCl-extractable nonexchangeable K) or with the clay content (contents of fixed Nand NaBPh4-extractable nonexchangeable K). In a pot experiment in which rice plants were grown in soil from each plot for 50 d, the dry matter weight of shoots exhibited a large variation (CV 12%) and increased significantly with the increase of the level of the components related to the total C content, especially the content of mineralizable N. Significantly positive correlations were also found between the contents of N, P, and K in shoots and the corresponding soil nutrients occurring in a moderately labile form. These soil-plant relationships suggest that site-specific application of organic fertilizers for altering the level of the components related to the total C content in the topsoil could be effective to homogenize rice growth in the paddy field examined.  相似文献   

11.
高密市农田土壤养分空间变异特征研究   总被引：3，自引：3，他引：3  
以高密市为例,利用GIS和地统计学方法在县域的尺度上分析土壤有机质、全氮、碱解氮、有效磷、速效钾、有效锰、有效铜、有效锌、有效硼9种养分的空间变异情况,利用克里格插值分析土壤养分的空间分布格局。结果表明,有效磷变异系数最大为48.80%,有机质变异系数最小为21.76%,变异系数由大到小依次为有效磷>有效锌>速效钾>有效铜>有效硼>有效锰>碱解氮>全氮>有机质。各土壤养分都具有良好的半方差结构,除了有效锰符合线性模型以外,其他养分均符合指数模型。速效钾、有效铜、有效锌具有强烈的空间自相关性;有机质、全氮、碱解氮、有效磷、有效锰、有效硼具有中等强度的空间自相关性,自相关程度速效钾>有效铜>有效锌>有效硼>全氮>碱解氮>有机质>有效磷>有效锰。在空间自相关范围上,有效硼最大为28716 m,有效铜最小为1410 m。微量元素锰、硼在空间分布上呈现出明显的规律性,锰呈现出从北到南逐渐增加的趋势,而硼含量则是从北到南逐渐减小;有机质、全氮、碱解氮三种元素呈现出相似的空间分布格局;有效铜、有效锌没有明显的规律性;有效磷、速效钾高值区呈块状零星分布。该研究揭示了高密市土壤养分的空间分布规律,对于实施精准农业和耕地的可持续利用具有积极意义。  相似文献   

12.
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13.
ABSTRACT

The conducted studies show post-harvest residues of sowing/pea mixtures limit leaching of mineral nitrogen deeper into the soil profile compared to post-harvest residues of sowing peas, as they affect the yield and amount of nitrogen accumulated in hybrid winter rye grain. The objective of the study was to determine the effect of the post-harvest residue biomass of field pea, oat and their mixtures on yielding and quantity of nitrogen accumulated in hybrid winter rye grain. Two factors were examined: factor I ? post-harvest residues of field pea 100% ? pure stand, oat 100% ? pure stand, field pea 75%?+?oat 25%, field pea 50%?+?oat 50%, field pea 25%?+?oat 75%; factor II ? forecrop harvest date: the stage of field pea flowering, the stage of field pea flat green pod. The obtained results demonstrated that the lowest mineral nitrogen content in two soil layers was recorded following oat harvested at the stage of field pea flat green pod. The research revealed that hybrid winter rye cultivated after the mixture consisting of 50% field pea and 50% oat should be recommended for wide agricultural application in order to obtain high grain yield.  相似文献   

14.
Soil physical, chemical, and biological properties in a rice field located at the Surin Rice Research Center, Thailand, were evaluated as indicators for predicting organic rice (Kao Dok Mali 105 variety) production and yield. Four treatments under different management practices were studied. They included (1) conventional farming (CF) receiving chemical fertilizer application; (2) organic plot receiving green manure (GM) addition; (3) organic plot receiving rice straw (RS) addition; and (4) control plot (CT) without any external plant nutrient source. Soil quality in the four treatments was assessed based upon selected physical, chemical, and biological parameters. Key findings are as follows: cation exchange capacity (CEC), electrical conductivity (EC), pH, soil organic matter (SOM), and essential macronutrients [nitrogen (N), phosphorus (P), and potassium (K)] were low in all plots. Soil biological properties including potential N mineralization (PMN), soil basal respiration (BR), microbial biomass carbon (MBC) and microbial biomass N (MBN) in all treatments were also low. Principal component analysis (PCA), using 15 soil properties, showed significant differences among farm management practices. Soil chemical and biological properties best related to soil quality included P, N, and SOM (for chemical properties) and MBC, MBN, and BR (for biological properties). Based on significant relationships between yield (r > 0.75) and the soil properties (r > 0.55), selected soil biological (MBC, MBN, and BR) and chemical (TOP [total organic phosphorus], TK [total potassium], TN [total nitrogen], SOC [soil organic carbon], and SOM) properties were determined to be suitable soil-quality indicators, respectively. A soil-quality indicator for predicting rice yield was computed using multiple regression analyses. The regression model (Y = ?1.685 + 0.333 (MBN) + 0.640 (TK) ? 0.282 (SOC), r2 adjusted = 0.962) was used for predicting yield. Grain yield of rice (RMSE = 0.046 t ha?1, D index = 0.45) was obtained using this regression model.  相似文献   

15.
ABSTRACT

Soil water and nutrient availability are major limiting factors for crop production in the Canadian prairies. Most variations in soil properties observed across prairie farm fields are the result of the effect of landscape on water and soil redistribution. The relationships among soil chemical properties (pH, electrical conductivity, organic matter, and available nutrients), soil water, elevation, and canola seed yield were investigated in a transect across a hummocky, undulating farm field in the Brown soil zone of south-central Saskatchewan. Overall, seed yield was highest in foot slope positions in the landscape where soil organic matter, nutrients, and available water content were higher. Correlations between soil properties and seed yield were highest for pH (R = ?0.46, P < 0.01), which was followed by organic C % (R = 0.27, P < 0.05), water content (R = 0.23), extractable potassium (K) (R = 0.18) and nitrogen (N) and phosphorus (P) supply rates to exchange resin membranes (R = 0.15). Extractable N and P were poorly correlated with seed yield (R < 0.1). The landscape region with soil parameters and yield closest to the average for the entire transect was the back slope region, suggesting that in similar landscapes, this region would be most appropriate for selection as a representative benchmark sampling site.  相似文献   

16.
南方花岗岩红壤典型区土壤有机质的空间变异特征   总被引：1，自引：0，他引：1       下载免费PDF全文
 通过野外实地调查与室内试验,以长汀县为研究区,在GIS的支持下,运用地统计学方法分析南方花岗岩红壤典型区表层土壤有机质的空间变异特征。结果表明:研究区土壤有机质质量分数总体水平中等并具有中等的空间相关性,平均为2.73%;变异系数为72.73%,属中等变异;由空间自相关部分引起的空间变异性程度较大,C0/(C0+C)值为47.13%,变程为21.48km;在空间分布上呈现四周高中间低的分布特征,在中部地区形成连片的低值区,西部有机质质量分数整体较高,存在最高值。研究成果可为南方花岗岩红壤侵蚀退化地的生态恢复与重建提供参考。  相似文献   

17.
Abstract

An irrigated farmer's field at Hafizabad village in Dera Ismail Khan District of Northwest Frontier Province of Pakistan was sampled at a regular grid spacing of 50x15 m from surface (15 cm) to study the spatial variability of soil properties and wheat yield. The farm measured 250x75 m. Soil samples collected were analyzed for soil pH, lime content, organic matter, mineral nitrogen (N), ammonium bicarbonate (AB)‐DTPA‐extractable phosphorus (P) and potassium (K), and soil texture. A uniformly trial on wheat with a uniform rate of 120 kg N ha‐1, 90 kg P2O5 ha‐1, and 60 kg K2O ha‐1 was laid out. The results showed that the soil P had the highest coefficient of variation (CV 46%) followed by organic matter (36.20%) and clay content (33.81%). Grain yield had also a considerable variation in the field (CV=31.84%). Geostatistical technique of semivariogram analysis showed that mineral N, AB‐DTPA‐extractable K, sand, silt, and clay content had the strong spatial structure. Maps of soil fertility and crop productivity of the farm was prepared using modern geostatistical technique of kriging. The farm was divided into different management zones based on these maps for fertility management.  相似文献   

18.
Li  Yuqian  Ma  Junwei  Xiao  Chen  Li  Yijia 《Journal of Soils and Sediments》2020,20(4):1970-1982
Purpose

Soil nutrients, elemental stoichiometry, and their associated environmental control play important roles in nutrient cycling. The objectives of this study were (1) to investigate soil nutrients and elemental stoichiometry, especially potassium and its associative elemental stoichiometry with other nutrients under different land uses in terrestrial ecosystems; (2) to discuss the impacts of climate factors, soil texture, and soil physicochemical properties; and (3) to identify the key factors on soil nutrient levels and elemental stoichiometry.

Materials and methods

Soil data, including pH, bulk density (BD), cation exchange capacity (CEC), volumetric water content (VMC), clay, silt and sand contents, total carbon (TC), nitrogen (TN), phosphorous (TP) and potassium (TK), available nitrogen (AN), phosphorus (AP), potassium (AK), and soil organic matter (SOM) under different land-use types, were collected, and their elemental stoichiometry ratios were calculated. Climate data including temperature, precipitation, relative humidity, wind speed, and evapotranspiration were collected. The least significant difference test and one-way analysis of variance were applied to investigate the variability of soil nutrients and elemental stoichiometry among land-use types; the ordinary least squares method and the general linear model were used to illustrate the correlations between soil nutrients, elemental stoichiometry, and soil properties or climate factors and to identify the key influencing factors.

Results and discussion

Woodlands had the highest SOM, TN, AN, and AK contents, followed by grasslands, croplands, and shrublands, while the TP and TK contents only varied slightly among land-use types. SOM, TN, AN, N/P, and N/K were strongly negatively correlated to soil pH (p <?0.05) and were strongly positively correlated to soil CEC (p <?0.05). For soil texture, only C/N was moderately negatively correlated to silt content but moderately positively correlated to sand content (p <?0.05). For climate factors, SOM, TN, AN, N/P, and N/K were significantly negatively correlated to evapotranspiration and temperature (p <?0.05), and the correlations were usually moderate. Soil pH explained most of the total variation in soil nutrients, and climate factors explained 5.64–28.16% of soil nutrients and elemental stoichiometry (except for AP (0.0%) and TK (68.35%)).

Conclusions

The results suggest that climate factors and soil properties both affect soil nutrients and elemental stoichiometry, and soil properties generally contribute more than climate factors to soil nutrient levels. The findings will help to improve our knowledge of nutrient flux responses to climate change while also assisting in developing management measures related to soil nutrients under conditions of climate change.

  相似文献   

19.
邢喆  黄标  董成森  孙维侠  胡文友  田康 《土壤》2013,45(3):405-411
在2011年土壤采样的基础上,参照1981年沭阳县二次土壤普查资料,对该县土壤有机质和全氮30年来的时空演变进行了分析,并进一步讨论了时空演变的自然和人为因素.结果表明:30年来,沭阳县农田耕层(0～20cm)土壤有机质和全氮均明显增加,2011年土壤有机质和全氮的平均含量分别为23.12 g/kg和1.36 g/kg,分别比1981年增加了12.15 g/kg和0.61 g/kg,平均增加速率达0.41 g/(kg·a)和0.02 g/(kg.a).2011年土壤有机质和全氮的整体空间分布格局与1981年相似,均呈现北部黏性土壤高而南部砂性土壤低、东部水田高西部旱地低的空间分布格局.土壤质地是造成这种时空变异最主要的结构性因素,而秸秆还田量的增加、土地利用方式的转化是30年来影响土壤有机质和全氮时空演变的主要人为随机性因素.  相似文献   

20.
土地开发对农田土壤养分和盐分变异特征的影响   总被引：2，自引：0，他引：2  
武红旗  谷海斌  陈冰  盛建东 《土壤》2012,44(1):90-94
利用地统计学方法研究了新疆库尔勒市包头湖农场土地开发后土壤空间变异特征。结果表明:土地开发后种植区的土壤有机质和盐分降低,有效磷含量增加,碱解氮含量变化不大;尤其是土地开发后撂荒地土壤有机质含量下降明显。土壤盐分与有机质、碱解氮及速效钾的含量均呈显著正相关,与有效磷呈显著负相关。因此,土地开发后需增施有机肥,补充钾肥,并尽可能不撂荒。  相似文献   

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