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1.
Koji Yamane Ranee C. Mabesa-Telosa Ryosuke Tajima Nino P. M. C. Banayo Yoichiro Kato 《植物养料与土壤学杂志》2019,182(1):28-30
Simple tools for diagnosing crop nutritional status are in great demand by agricultural extension staff, particularly in low‐fertility environments. We developed the first practical method for in situ diagnosis of phosphorus (P) nutrition in field‐grown cereal crops by using a handheld colorimeter. The concentration of P in extracts from fresh leaves of lowland rice grown under various P availabilities was closely correlated with that of oven‐dried leaves measured with the standard molybdenum‐blue method in the laboratory, over a range of values from 0.319 to 1.420 mg P g ?1 DW (r = 0.885**, n = 14). It takes only 3–5 min to estimate the P concentration of plant samples using the new technique. Although not as accurate as the laboratory method, the new method can easily detect P deficiency of rice in the field (and possibly other cereal crops) without requiring costly, off‐site equipment. Thus, extension staff and agronomists can easily adopt this technique. 相似文献
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不同轮作模式农田磷养分表观平衡及其对土壤Olsen-P含量的影响 总被引:1,自引:0,他引:1
通过连续3年监测上海郊区43块定位农田研究,比较了50种作物以及5种不同轮作模式农田的磷养分表观盈余状况及其对土壤Olsen-P含量的影响。结果表明:(1)不同作物农田的磷养分盈余趋势为水生蔬菜类果树类旱作蔬菜≥草皮大田作物;不同轮作模式农田磷养分盈余趋势为菜菜轮作果树单作菜作轮作草皮单作作物轮作;(2)不同作物及轮作农田收获后土壤Olsen-P含量随土壤深度的增加而逐渐降低,磷养分盈余量多的农田土壤Olsen-P含量也高;(3)不同作物以及轮作农田磷养分盈余与收获时土壤表层(0~30cm)的Olsen-P含量呈显著正相关。 相似文献
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On the basis of long‐term fertilization experiments in Skierniewice, being conducted since 1923 at the Experimental Field of Warsaw Agricultural University, the fate (or balance) of nitrogen for a period of 35 years and that of phosphorus and potassium for 20 years, was studied. The balance includes N, P and K rates applied in mineral fertilizers and farmyard manure (FYM), uptake of these nutrients by the crop plants and the changes in the content of total N and total P and of slow release K in the soil during that time. The nitrogen balance shows a loss of this nutrient of 11—14 kg N ha—1 y—1, which corresponds to 15% of the applied ammonium nitrate on fields without FYM but to 23% on fields with FYM, in spite of crop yields being considerably greater on fields treated with FYM. The phosphorus balance indicated that in the 0—70 cm soil layer less than 4% of P from superphosphate was not found. In the treatment not fertilized with potassium for many years, the plants took up 49 kg K ha—1 y—1 from slow release forms because the fraction of available K did not change during that period. When calculating the potassium balance only 1.6% of K from potash salt were not found in plots without FYM but 12.3% of the applied KCl were not recovered in treatments with FYM. The comparison of the P‐ and K‐uptake from organic and mineral fertilizer in the two crop rotations indicates a higher P‐ and K‐efficiency from FYM than from inorganic fertilizer. 相似文献
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施用常规磷水平的80%可实现玉米高产、磷素高效利用和土壤磷平衡 总被引:5,自引:2,他引:5
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Walter E. Riedell 《植物养料与土壤学杂志》2010,173(6):869-874
Nitrogen (N)‐fertilizer applications to field‐grown maize may result in a dilution response whereby essential mineral‐element concentrations in shoots would decrease as shoot‐dry‐matter accumulation increased. To investigate this, the effect of N‐fertilizer treatments (no N or fertilizer rate based upon 5.3 or 8.5 t ha–1 yield goal) on maize (Zea mays L.) shoot dry weight and shoot mineral concentrations (N, P, K, S, Mg, Ca, and Mn) at the sixth leaf (V6), twelfth leaf (V12), and tassel (VT) development stages were investigated in a 2‐year study conducted at Brookings, South Dakota (USA). With increasing N‐fertilizer application rates, shoot dry weight was greater and shoot P and K concentrations decreased. A possible explanation of this dilution response is that planting‐time P and K fertilizers, which were applied in a band near the seed furrow, may have enhanced the uptake of P and K in a manner that was independent of N‐fertilizer treatments. Increased shoot‐dry‐weight production due to the application of N fertilizers, if P and K uptake were similar across N‐fertilizer treatments, would lead to decreased shoot P and K concentrations in N‐sufficient compared with N‐deficient plants. Conversely, N‐fertilizer‐induced increases in shoot dry weight were accompanied by increased shoot concentrations of N, Ca, and Mn. This synergistic response between dry‐weight accumulation and shoot N concentration was present at all leaf developmental stages studied, while that for Ca was present only at VT. Thus, N fertilizer applications that increase shoot dry weight can affect the dilution and synergistic responses of specific mineral nutrients in maize shoots. Crop developmental stage as well as the location of these specific mineral nutrients in the soil profile might play important roles in mediating these responses. 相似文献
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Methods for estimating sediment and phosphorus (P) transfer from agricultural land to surface waters are needed to mitigate their adverse impact on water quality. This study quantified sediment and P losses from five agricultural fields and evaluated the patterns observed based on the intrinsic risk of sediment and P mobilization from the soil, together with field topographical and hydrological data. The mobilization risk was estimated using the environmental soil dispersion test DESPRAL. High‐resolution LiDAR elevation data and crop management data were used to describe transport and delivery of the material mobilized. Annual flow‐weighted suspended solids (SS) concentration in drainage water ranged from 48 to 374 mg/L, total P (TP) from 0.12 to 0.39 mg/L and unreactive P (UP) from 0.08 to 0.33 mg/L. The mobilization risk, measured as turbidity in the aliquot recovered from the dispersion test, varied from 781 to 2310 nephelometric turbidity units (NTU). The method proved to be efficient in describing and differentiating sediment and P mobilization potential between fields. The topographical data also showed large differences between fields, with the length–slope (LS) parameter varying from 0.037 to 0.999. Based on assessments of source (mobilization risk) and transport factors (LS, crop management data), it was possible to characterize fields as favoured or limited in terms of source and transport and to explain the long‐term SS and P losses observed at field scale. 相似文献
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The loss of nutrients by wind erosion is generally attributed to losses by suspension, since suspension selectively removes the finest particles. However, because the main mass of sediment is moved by saltation during an event, the main mass of nutrients is also moved by saltation. Nutrient losses from one field during one wind erosion event can be as high as 73 per cent of the N and 100 per cent of the P needs for crop production. Vegetated areas have a higher dust deposition because of the filtering effect of the vegetation and the reduction of drag forces causing a higher deposition. This refutes the general assumption that deposition of suspended dust is homogeneous for a larger area. In the Sahel, two types of dust can be distinguished, the Harmattan dust is richer in nutrients and regarded as a real input of nutrients. The convectional storm dust has a nutrient content comparable with the nutrient content of the dust fraction of the topsoil and can't be regarded as input of nutrients. From research on nutrient losses by water erosion at the plot scale, it is concluded that nutrient erosion by water can cause serious losses of nutrients. But at the village scale, the losses are considerably smaller than at the plot scale. Measurement and subsequent nutrient budget analyses around the village Dangadé in Burkina Faso indicated that this area is especially vulnerable for wind erosion by saltation transport. This demonstrates that in the Sahelian environment, the effect of wind erosion at the village scale can't be ignored. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Characterization of field‐scale dryland salinity with depth by quasi‐3d inversion of DUALEM‐1 data
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J. Huang T. Kilminster E. G. Barrett‐Lennard J. Triantafilis 《Soil Use and Management》2017,33(2):205-215
To understand the limitations of saline soil and determine best management practices, simple methods need to be developed to determine the salinity distribution in a soil profile and map this variation across the landscape. Using a field study in southwestern Australia, we describe a method to map this distribution in three dimensions using a DUALEM‐1 instrument and the EM4Soil inversion software. We identified suitable parameters to invert the apparent electrical conductivity (ECa – mS/m) data acquired with a DUALEM‐1, by comparing the estimates of true electrical conductivity (σ – mS/m) derived from electromagnetic conductivity images (EMCI) to values of soil electrical conductivity of a soil‐paste extract (ECe) which exhibited large ranges at 0–0.25 (32.4 dS/m), 0.25–0.50 (18.6 dS/m) and 0.50–0.75 m (17.6 dS/m). We developed EMCI using EM4Soil and the quasi‐3d (q‐3d), cumulative function (CF) forward modelling and S2 inversion algorithm with a damping factor (λ) of 0.07. Using a cross‐validation approach, where we removed one in 15 of the calibration locations and predicted ECe, the prediction was shown to have high accuracy (RMSE = 2.24 dS/m), small bias (ME = ?0.03 dS/m) and large Lin's concordance (0.94). The results were similar to those from linear regression models between ECa and ECe for each depth of interest but were slightly less accurate (2.26 dS/m). We conclude that the q‐3d inversion was more efficient and allowed for estimates of ECe to be made at any depth. The method can be applied elsewhere to map soil salinity in three dimensions. 相似文献
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The nitrogen, phosphorus and potassium balances for agriculture in Germany during the period 1970 to 1995 (western states) and 1990 to 1995 (entire Germany including the states of the former German Democratic Republic), respectivly, are calculated according to the PARCOM guidelines. The surplus of the basic national mineral balance is subdivided into the crop production surplus and the livestock production balance surplus. In the former West German states, P and K basic surpluses have declined about 60% since 1980, while the N-surplus has dropped 23% since 1987. The efficiency of agricultural nutrient use has improved correspondingly. A sensitivity analysis and an error estimation reveal the accuracy of the results. The relevance and limits of interpreting nutrient balances on a national scale are clarified by a critical appraisal of the balance surplus values. 相似文献
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黄土丘陵区不同类型农地的养分循环平衡特征 总被引:3,自引:1,他引:3
该文以黄土丘陵沟壑区的安塞试验站长期肥料定位试验的实测资料为研究对象,定量研究川地、坡地、梯田不同类型农地养分循环特征。研究结果表明:川地、坡地、梯田与农民习惯施肥水平相类似的处理,年养分盈亏量分别是:川地每年每hm2氮素盈余10.2 kg,P2O5盈余56.6 kg;坡地每年每hm2氮素亏损7.0 kg,P2O5亏损14.7 kg;梯田每年每km2氮素盈余104.9 kg,P2O5盈余107.3 kg。退耕还林和实施“坡改梯”工程是黄土丘陵沟壑区农地养分循环不断朝良性方向发展的关键措施。 相似文献
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The equivalence of the Calcium‐Acetate‐Lactate and Double‐Lactate extraction methods to assess soil phosphorus fertility
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Michael van Laak Uwe Klingenberg Edgar Peiter Thomas Reitz Dana Zimmer Uwe Buczko 《植物养料与土壤学杂志》2018,181(5):795-801
A large variety of extraction methods are used worldwide for the estimation of “plant‐available P” in soils. In Germany, the standard extractants are Calcium‐Acetate‐Lactate (CAL) and Double‐Lactate (DL). Until now there is no validated transformation procedure available and studies on the comparability of both methods have reported conflicting evidence. The uncertainty about the equivalence of CAL‐P and DL‐P hinders a direct comparison of the P fertility status and P fertilizer recommendations across Germany. Based on 136 datasets for soil samples from an interlaboratory comparison program and three P fertilization field trial sites, for which plant‐available P had been determined by both the CAL and DL method, we assessed the comparability of both extraction methods and derived simple and multiple regression equations to transform DL‐P into CAL‐P values. On average, DL extracted 30% more P than CAL. However, this strongly depended on soil pH and carbonate content. A simple linear regression model explained 70% of the variance. However, if simple linear regression models were fitted to pH‐specific samples (pH range 4.5 to 7.0) the R2 increased to 0.96. Based on an independent validation dataset (n = 48) we demonstrated that such pH‐specific models were more accurate than models that did not consider pH when transforming DL‐P to CAL‐P values. Multiple regression results showed that out of soil pH, Corg, Nt, and C : N ratio, only soil pH improved the model. The transformation equations in this study provide a step towards an improved comparability of P fertility status assessments of soils across Germany. 相似文献
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B. Kronvang N. Vagstad H. Behrendt J. Bøgestrand & S. E. Larsen 《Soil Use and Management》2007,23(S1):104-116
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长期不同施肥下南方黄泥田有效磷对磷盈亏的响应特征 总被引:6,自引:2,他引:6
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东北黑土区是中国商品粮的主产区,近年来存在耕地“变薄、变瘦、变硬”等土壤质量下降问题。农业废弃物作为碳源高效还田是提升土壤质量的重要途径,但目前缺少基于农业-牧业碳素循环调控的区域农业生产系统模式,以促进碳素高效还田和黑土地地力提升。为了探讨基于土壤碳收支平衡来调整农牧规模的方法,该研究选取位于松嫩平原腹地的齐齐哈尔市作为研究对象,核算齐齐哈尔市各县域土壤碳收支状况,以土壤碳排放和碳输入相平衡为目标,通过多目标线性规划方法构建齐齐哈尔市的农牧业碳平衡农业模式。结果表明,各县域主要调整方案为种植业需要减少水稻种植面积,增加玉米的种植面积,养殖业需要增加奶牛养殖规模。调整后种植业和养殖业的废弃物得到全量化利用后,农田土壤碳库不再下降。县域尺度农牧规模需因地制宜的调整,以土壤碳亏损较大的讷河县为例,在保证碳输入及农业经济收益的基础上,增加46%的玉米种植面积,减少63%的黄牛养殖规模,增加85%的奶牛,54%的生猪,76%的羊及71%的家禽养殖规模,可保持土壤碳平衡。种植业和养殖业规模调整后的有机物料还田可替代33%~49%的化肥氮投入,除克东县和克山县的玉米种植外,3种主栽作物的土壤氮承载... 相似文献
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The “phosphorus index” (PI) is a semiquantitative tool to assess the risk of P loss from fields to surface waters, which is based on simple arithmetic computations of source (soil test phosphorus (STP), P applications as manure and fertilizer, plant residues) and transport factors (erosion, surface runoff, subsurface drainage, connectivity). Work done since the 1990s in the U.S.A. and several European countries has shown that this approach is capable of delineating critical source areas for P export within a watershed. It is intended to adopt such a PI tool in Germany as well. However, there is no “standard” PI, and the variety of P indices is confusing, since each state and country has developed its own version to account for special regional conditions which are important for P loss. This paper reviews the factors of P loss which are taken into account in P indices and different modifications of P indices according to their components and structural approach. The literature concerning single source and transport factors of P loss is overwhelming, and a structured selection is given in this review. Most P indices can be classed into one of three groups: 1. additive approach, 2. multiplicative approach, and 3. multiplicative‐additive approach. For Germany, it is suggested that specific factors of P loss are incorporated into the basic backbone of a Pennsylvania‐style PI. Realization of the factors could be adopted from existing Scandinavian P indices or from other research results. 相似文献
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Accumulation of phosphorus (P) in agricultural topsoils can contribute to leaching of P which may cause eutrophication of surface waters. An understanding of P mobilization processes in the plough layer is needed to improve agricultural management strategies. We compare leaching of total dissolved and particulate P through the plough layer of a typical Danish sandy loam soil subjected to three different P fertilizer regimes in a long‐term field experiment established in 1975. The leaching experiment used intact soil columns (20 cm diameter, 20 cm high) during unsaturated conditions. The three soils had small to moderate labile P contents, expressed by water‐extractable P (3.6–10.7 mg/kg), Olsen P (11–28 mg/kg) and degree of P saturation (DPS) (25–34%). Mobilization of total dissolved P (TDP) increased significantly (P < 0.05) from the intact soil columns with increasing labile P, whereas the increase in particulate P (PP) with increasing labile P content was modest and statistically insignificant. We found concentrations up to 1.5 mg TP/L for the plough layer of this typical Danish sandy loam soil. This highlights that even a moderate labile P content can be a potential source of TDP from the plough layer, and that a lower concentration margin of optimum agronomic P levels should be considered. 相似文献
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After the political changeover in Hungary in 1989, many farm owners faced problems typical of a small sized farm (<1 ha) as well as a lack of various resources. This led to many farms with great horticultural backgrounds being abandoned, especially in mountainous areas where erosion control is essential for soil conservation. Severe changes can occur on soil through property abandonment. The local socio‐economic aspects must be taken into consideration as well as the problem of soil degradation as this will be a motivating factor in preservation initiatives. Under horticultural management, Mahonia aquifolium was tested to determine its efficiency in water erosion control in mountainous conditions in Hungary. Soil loss and water runoff were measured after every rainfall event at six different plots: four cultivated M. aquifolium populations with different ages (4, 12, 20 and 25 years old) and two control plots. A bare soil field and a grass field represented the control plots. The results show that as the age of the M. aquifolium populations increase, the cumulative runoff and sediment values decrease. It also showed that 2 years after setting up a new M. aquifolium plantation, the cumulative runoff decreased by 69 per cent and the cumulative soil loss decreased by 74 per cent. This indicates that a M. aquifolium population could play a significant role in erosion control within a short period of time. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献