Spatial variability of soil properties and wheat yields in an irrigated field

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.     

A quick test procedure for soil nitrate‐nitrogen

Abstract

A procedure for extraction and measurement of nitrate‐nitrogen (NO₃‐N) in soil is described. Extracting solution [0.025M Al₂(SO₄)₃] and field‐moist soil are measured volumetrically, with NO₃‐N concentration measured by nitrate‐sensitive colorometric test strips or nitrate‐selective electrode. Across a range of soil texture, moisture content, and NO₃‐N concentration, the procedure was well correlated with conventional laboratory analysis of 2N KC1 soil extracts (r² = 0.94). This quick test procedure is proposed as an on‐farm monitoring technique to improve N management.     

Effect of Incorporation of Crop Residues on a Maize–Groundnut Sequence in the Humid Tropics. II. Soil Physical and Chemical Properties

Abstract

A two‐year study (1997–1999) was conducted on a sandy clay loam (Typic Paleudult) at the experimental farm of the Universiti Putra to determine the effects of application of crop residues on changes of some soil properties in a maize (Zea mays L.)–groundnut (Arachis hypogaea) crop rotation system. Five crops of a rotation of sweet corn–groundnut–sweet corn–groundnut–sweet corn were sown with three treatments: recommended inorganic fertilizer [nitrogen (N), phosphorus (P), and potassium (K)] with crop residue (T1), recommended inorganic fertilizer without crop residues (T2) or one‐half of the recommended inorganic fertilizer with crop residues combined with 10 t ha^?1 of chicken manure (T3). Soil organic carbon (OC), soil water content and soil bulk density were not significantly changed. Application of crop residues for two years increased cation exchange capacity (CEC) whereas supplementing crop residues with CM had significantly increased soil pH of the topsoil. Phosphorous in manure treatment had moved down the soil profile, which might cause eutriphication of under ground water, particularly during the rainy season. Based on this work, incorporation of crop residues could be a beneficial practice for improving the fertility of acid soils.     

Nitrogen and Phosphorus Balances of Hungarian Farms as Management Tools for Sustainable Agriculture

Abstract

At the moment, Hungarian agriculture is confronted with a certain duality as far as nutrients are concerned. On the one hand, national soil nutrient balances show substantial deficits, and on the other hand, agricultural nutrient use is responsible for a part of the nitrogen (N) and phosphorus (P) losses to the environment. To understand this duality and help optimize farm nutrient management, the farm gate N and P balances of 12 farms, representing a variety of Hungarian agriculture, were calculated for the year 2002. The farm gate N and P surpluses/deficits in the east of the country were lower than in the west. This was correlated with a lower fertilization rate. The low soil fertility level due to a prolonged period of low fertilization in combination with continuing nutrient deficits can lead to possible future reduction in crop yields.     

Sustainability of organic fertilization of macadamia with macadamia husk‐manure compost

Abstract

Macadamia husk‐manure compost was evaluated as an organic fertilizer for the production of macadamia in an experiment over four years at irrigated and unirrigated sites on the MacFarms of Hawaii orchard. The treatments were (1) Fertilizer, a combination of solid and liquid chemical fertilizers applied based on leaf and soil analysis, (2) Compost, 10,000 kg ha^‐1 of a macadamia husk‐cattle manure compost alone applied annually between July and October, and (3) Compost+, compost plus mineral fertilizers applied based on leaf and soil analysis. In‐shell nut and kernel yield and quality were higher at irrigated than unirrigated sites, but were not significantly affected by the treatments. Change in leaf nutrient composition appears minimum except for slightly lower nitrogen (N) and boron (B) at two orchard sites for the compost treatment. Compost increased soil pH, total ion exchange capacity, soil organic matter, potassium (K), calcium (Ca), magnesium (Mg) at all sites, and sodium (Na) at irrigated sites. Soil nitrate (NO)‐N was lower in the compost treatment. Fertilization with compost was not profitable because the cost of compost application exceeded conventional fertilization cost tenfold for MacFarms, the largest macadamia farm in the United States.     

Influence of Manuring on certain soil physical properties in the middle awash area of ethiopia

Abstract

Irrigated soils in Middle Awash area of Ethiopia have poor aeration and low water infiltration rates. In order to improve these characteristics, green manure (dolicus lab‐lab), farm yard manure, and bagasse were incorporated into the soil. As a result, grain and dry matter yields were statistically significantly improved. However, dry matter and grain yield from the application of bagasse were lower even than the control treatment Infiltration rates and bulk density were also measured before and after application of green manure, farm yard manure, and bagasse. Infiltration intake rates before incorporation of dolicus lab‐lab was slightly increased. In contrast, lighter bulk density and total soil porosity were obtained before incorporation of farm yard manure. Overall green manure may be regarded as one of the most promising organic manures in improving certain degraded soil physical properties.     

Assessment of Properties of a Harkey Soil under Organic and Conventional Farming Systems

Farming practices involving less intense chemical use are becoming popular in the United States primarily because of environmental concerns related to the use of chemicals in conventional farming systems. Physical and chemical soil properties were assessed on four farms, one conventional farm and three organic farms 3 (OF3), 6 (OF6), and 9 (OF9) years after certification. All farms were located in Doña Ana County of southern New Mexico, sited on Harkey soil (coarse silty, mixed, calcareous, thermic typic Torrifluvents). OF3, OF6, and OF9 were planted to cotton (Gossypium arboreum L.), chile (Capsicum annuum), and alfalfa (Medicago sativa) in 2006, respectively, and the conventional farm was planted to cotton. Core and bulk soil samples were collected from each farm at three different locations and three depths during September 2005, June 2006, and November 2006. Clay content was positively correlated with field capacity, wilting point, and available water capacity (AWC) and negatively correlated with transmission pore volume (VTP) and sand content at most depths. The one-way analysis of means of soil physical and chemical properties separately by depth showed that bulk density (ρ_b) was greater in November 2006 samples than in September 2005 and June 2006 samples in OF9 and was lowest in the conventional farm. In general, saturated hydraulic conductivity (K_s), volume of storage pores, effective porosity, AWC, and VTP showed little variation and were not related to the amount of time under organic farming. Soil pH and electrical conductivity (EC) were greater in the organic farms, and EC values mostly increased with increasing amount of time under organic farming. The greatest EC (2.6 dS m^?1) in OF9 indicated that 9 years of manure application has raised soil salinity only slightly. Although no evidence on significant improvement of soil quality due to organic farming was observed, with regard to soil storage and transport properties and soil salinity, the organic farming system is sustainable for this region.     

Mineral composition of tobacco leaf samples part II: As affected by soil fertility,seasonal variation,and stage of growth

Abstract

Three tobacco varieties were grown for three consecutive years on plots that were fertilized to produce a 2X2 factorial of soil acidity and soil fertility. Leaf samples and height measurements were taken periodically each year. The plant samples were analyzed for eleven elements. Rainfall differences among years provided information concerning the seasonal moisture effects on the treatment variables. Data presented show that the stage of growth, the soil fertility and acidity and the relative moisture stress affect tobacco height and the mineral composition of tobacco leaves. The information can be useful in assigning magnitude and direction for plant age and climatic interactions in practical diagnostic work.     

Improvement in physical quality of a Sahelian Arenosol and implications on millet yield

Poor soil fertility remains a threat to crop production and livelihoods in the Sahel. Understanding the impacts of proposed soil fertility management technologies on soil fertility status and millet yield is essential. We conducted a 2-year experiment to assess changes in selected physical properties of an Arenosol and their impacts on millet yields at Karabedji, Niger. Treatments consisted of four fertilizer rates applied on top and bottom farm types selected from a long-term experiment. Mixed-model analyses indicated considerable effects (P = 0.055) of fertilizer rates and farm types on soil structural stability being higher in the top farm than in the bottom farm type. Dexter’s soil physical quality index (S) varied significantly with soil depth. A significant correlation (R² = 0.24) was found between the aggregate stability index and S. Plant available water recorded in fertilizer-treated soil was higher than the control and higher on the top farm than in the bottom farm. Fertilizer rates and farm types influenced millet yields. Moreover, we obtained positive relationships between millet yield and soil aggregate stability, and plant available water, thereby elucidating the significant role played by soil physical properties in influencing crop yields. S can be a simple way for assessing the physical quality of Sahelian sandy soil.     

Sorption and Fractionation of Copper in Soil at a Sewage Irrigation Farm in Australia

Abstract

Copper (Cu) is an important heavy metal to be considered in soil contamination, because high concentrations of copper in soil produce toxic effects and may accumulate in plant tissues. In Australia's oldest sewage irrigation farm, located in Werribee, Victoria, soil in the land filtration area is contaminated by Cu. However, Cu content in herbage tissues is in the normal range and has been trending downward since 1979. Therefore, studies on the sorption capacity and sequential extraction of Cu in soil at the Werribee Farm is of significance, not only for better understanding the mechanism of transport, chemical processes, and plant uptake of Cu, but also in providing information for the practical management of sewage farm soils. Methods of combining sorption isotherms with sequential extraction procedures were adopted, and the results showed that the soil in the land filtration area at Werribee Farm has a high sorption capacity for Cu, and distribution coefficients, K_f of Cu, were 629 L kg^?1 in surface soils (0–20 cm) and 335 L kg^?1 in subsurface soils (20–40 cm). The sequential extraction fractions demonstrate that exchangeable and carbonate fractions are very low, only comprising 3.49 to 5.49% of total copper. The other fractions are also discussed. This characteristic of Cu in soil is related to the low concentration of Cu in plant tissues.     

Housefly Larvae (Musca domestica) Vermicompost on Soil Biochemical Features for a Chrysanthemum (Chrysanthemum morifolium) Farm

ABSTRACT

The housefly larvae (Musca domestica) vermireactor is capable of highly efficient waste reduction for swine manure management; however, effectiveness of larvae-vermicompost land utilization and the associated impact on soil environment are poorly understood. This study, which integrated incubation pot experiments and field plot tests on a chrysanthemum (Chrysanthemum morifolium) farm, was designed to investigate soil biochemical and microbial functions in response to inorganic fertilizer (NPK), vermicompost (VC) application, and/or combination of inorganic fertilizer and vermicompost (I + V). Pot experiments indicated that available soil nitrogen (N), phosphorus (P), and potassium (K) were significantly higher (21%-43%, 206%-306%, and 35%-36%, respectively) with VC treatment compared to NPK treatment; meanwhile, soil organic carbon (C), N and P mineralization was increased by 46%-57%, 53%-70%, and 30%-113%, respectively. Vermicompost application increased soil highly labile organic C by 19% to 42%. Vermicompost also enhanced soil enzymatic activities: 37%-68% for dehydrogenase, 22%-107% for urease, and 3.4%-56% for phosphatases, but activities of soil β-1,4-glucosidase and β-1,4-N-acetylglucosaminidase were reduced by 17%-53% and 24%-42%, respectively. Compared to pot experiment, continuous land application of vermicompost overwhelmingly caused soil nutrient accumulation, increased soil C stock and microbial biomass, enhanced soil mineralization, and improved C-, N-, and P-related enzymatic activities. Co-inertia analysis indicated that soil fertility indices positively correlated with most microbiological indices. This work reveals VC as a new biofertilizer for crop production and highlights its merit on soil health improvement.     

Comparative Effects of Organic and Inorganic Fertilizers on Soil Organic Carbon and Wheat Productivity under Arid Region

ABSTRACT

Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha^?1 N, P₂O₅, and K₂O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha^?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R ² = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha^?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment.     

Available soil nutrients and water content affect leaf nutrient concentrations and stoichiometry at different ages of Leucaena leucocephala forests in dry-hot valley

Purpose

The carbon (C), nitrogen (N), and phosphorus (P) concentrations of leaves can reflect soil nutrient supply conditions and changes in soil. An understanding of species adaptability and nutrient use efficiency in extreme ecosystems can help land managers choose effective methods to improve management and community structure of introduced plants which may induce biological invasion and limit the regeneration of native species.

Materials and methods

We selected the Leucaena leucocephala forests in three ages (9, 15, and 26 years old) in the Jiangjiagou Gully to study the relationships between (i) soil factors and forest age and (ii) leaf nutrient concentrations. Soil factors and leaf nutrients were measured in nine sampling quadrats of 10?×?10 m of each plot. We used ANOVA to examine differences in leaf variables and soil factors at different ages of L. leucocephala forest. Pearson’s correlation analysis and linear regression analysis were conducted to identify the relationships between soil factors and leaf variables. Then, we used analysis of covariance to examine combined effects of forest ages and soil factors on leaf variables.

Results and discussion

Leaf N was significantly correlated with available P, while leaf P was significantly correlated with both available P and available N. Leaf N and P had no significant relationship with soil total N and P. Leaf C:N:P stoichiometries had a higher significant correlation with total N, available N, and soil water content.

Conclusions

Our findings illustrate that available N and available P are the main limitations for L. leucocephala, though available P imposed a stronger limitation than available N. Moreover, soil water content played an indispensable role on nutrient accumulation and the soil ecological environment. Our results provide useful information to improve L. leucocephala community structure and reduce soil degradation in a dry-hot valley.

     

Soil Properties,Yield, and Landscape Relationships in South-Central Saskatchewan Canada

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.     

Integrative Soil Application of Humic Acid and Sulfur Improves Saline Calcareous Soil Properties and Barley Plant Performance

ABSTRACT

During the 2017 and 2018 seasons, two field experiments were conducted on newly reclaimed saline calcareous soil (7.13 dS m^?1, 16.9% CaCO₃) in the experimental farm of the Faculty of Agriculture, Demo, Fayoum Governorate, Egypt. The current work aimed at identifying the potential positive effects of applied humic acid (HA) and elemental sulfur (S) on some soil properties and barley plant performance. The results showed that the application of HA and/or S at different rates ameliorated the adverse effects of saline calcareous soil conditions and significantly reduced some chemical properties of the soil (e.g., pH, ECe, and CaCO₃%), while soil organic matter (OM%) and some nutrients (e.g., P, Fe, Mn, Cu, and Zn) contents were significantly increased. In addition, the contents of nutrients (e.g., P, Fe, Mn, Cu, and Zn) in barley plant and yielded grain, grain content of N and protein (%), and the performance (e.g., plant height, spike length, grain and straw yields, and weight of 1000-grain) of barley plant were significantly increased with the application of HA and/or S. The best results were obtained through the integrative application of 100 kg HA + 400 kg S ha^?1 to the tested saline calcareous soil. Therefore, the integrative soil application of 100 kg HA + 400 kg S ha^?1 can be recommended for the cultivation and sustainability of crop production in saline calcareous soil, in addition to rationalize the use of mineral fertilizers, which represent a surplus point for the sustainable agriculture system.     

水土保持规划中低空遥感数据的获取及应用

[目的]为实现水土保持规划设计的高精度、高效率及现时性要求,探求低空遥感技术在水土保持规划设计中的应用基础和前景。[方法]选取陕西省榆林市横山区鲍家寺景区进行低空遥感试验,通过建立数字高程模型(DEM)和数字正射模型(DOM),从3个方面比较分析低空遥感数据的优势,并进一步探索了低空遥感成果在水土保持规划前期基础信息获取阶段的基本应用。[结果]低空遥感不但具有灵活性好,时效性好,数据精度高等基础优点,而且借助其他地理信息系统软件可方便、快捷提取地形现状信息和水土保持治理现状信息等水土保持规划基础资料,大大提高工作效率,能满足水土保持规划设计的要求。[结论]低空遥感数据应用于水土保持规划设计具备广阔前景。     

Influence of Applied Cattle Manure on Winter Wheat (Triticum aestivum L.) Grain Yield,Soil pH and Soil Organic Carbon

ABSTRACT

Animal manure is used in crop production to improve crop yield and soil properties. The impact of cattle manure applied in one year on yield and soil properties in the subsequent years has not been extensively studied. This work evaluated the effect of manure application on winter wheat grain yield (Triticum aestivum L.), soil organic carbon (SOC), and soil pH. Cattle manure was applied once every four years at a rate of 267 kg N ha^?1. Grain yield and soil samples (0–15 cm) were collected annually from the Magruder Plots, Oklahoma. Soil samples were analyzed using a glass electrode (pH) and LECO dry combustion analyzer (SOC). The highest yield (2.8 Mg ha^?1) occurred in the second year after manure application. Yield in the second year exceeded yield in the first year by 66%. Yields in the third and fourth year were similar to yields in the other years. No changes in soil pH and SOC were observed in each of the four years that constituted the manure application cycle. Cattle manure (267 kg N ha^?1) could be applied once to serve a four-year period without major yield differences while also improving soil pH and SOC when compared to the check.     

Nutrient content of maize and soil organic matter status under various tillage methods and farmyard manure levels

Abstract

A two-year field study was conducted under semi-arid conditions in Pakistan to assess the role of tillage systems and farmyard manure on soil, plant nutrients and organic matter content. Four tillage systems (zero, minimum, conventional and deep tillage) and three farm manure levels were used. Maize crop was grown up to maturity. Uptake of N, P and K in maize shoots improved in tillage systems compared to non-tillage and treatments where farmyard manure was applied. Soil N status decreased in the deep tillage systems, whereas it increased in all other tillage systems and in the farmyard manure amended treatments. Increase in soil P values was observed under minimum and conventional tillage, whereas deep tillage resulted in a decrease. Farmyard manure amendments increased soil P and soil K in all systems. Tillage did not affect soil K levels. Results demonstrate that reduced tillage is practicable in arid and semi-arid regions since it improves soil fertility.     

The Representative Soil Sampling Scheme of England and Wales: the spatial variation of topsoil nutrient status and pH between 1971 and 2001

The Representative Soil Sampling Scheme (RSSS) has monitored the soil of agricultural land in England and Wales since 1969. Here we describe the first spatial analysis of the data from these surveys using geostatistics. Four years of data (1971, 1981, 1991 and 2001) were chosen to examine the nutrient (available K, Mg and P) and pH status of the soil. At each farm, four fields were sampled; however, for the earlier years, coordinates were available for the farm only and not for each field. The averaged data for each farm were used for spatial analysis and the variograms showed spatial structure even with the smaller sample size. These variograms provide a reasonable summary of the larger scale of variation identified from the data of the more intensively sampled National Soil Inventory. Maps of kriged predictions of K generally show larger values in the central and southeastern areas (above 200 mg L^?1) and an increase in values in the west over time, whereas Mg is fairly stable over time. The kriged predictions of P show a decline over time, particularly in the east, and those of pH show an increase in the east over time. Disjunctive kriging was used to examine temporal changes in available P using probabilities less than given thresholds of this element. The RSSS was not designed for spatial analysis, but the results show that the data from these surveys are suitable for this purpose. The results of the spatial analysis, together with those of the statistical analyses, provide a comprehensive view of the RSSS database as a basis for monitoring the soil. These data should be taken into account when future national soil monitoring schemes are designed.     

基于侵蚀因子显性变化的区域水蚀动态监管方法研究

[目的]本着综合监管要完善机制、强化手段、严格追责的基本目标,提出一套基于侵蚀因子显性变化的区域水蚀动态监管方法,为制定精准的监督执法、检查、督导和违法违规查处的政策提供有效的方法支撑和精细的数据支持。[方法]在全面分析当前水土流失监管主要工作进展与存在问题的基础上,基于高分遥感影像、水土保持治理工程和生产建设项目前期设计资料等高空间精度、高现势性的数据,以土壤侵蚀地块为单元,精细识别侵蚀因子发生显性变化的对象,科学计算水土流失强度和面积的变化,查清引起变化的原因。[结果]侵蚀因子显性变化是指区域内某种或几种土壤侵蚀因子在局部发生变化,并呈现出显著的可被识别、可被监视的明确特征;显性变化集中体现在地块的地表坡度、土地利用类型、水土保持措施、植被覆盖度等变化。[结论]基于侵蚀因子显性变化的水土流失动态监管的技术和方法,尤其适用于年际间水土流失动态监测及其后续的监督管理。