Distribution Of Soil Chemical Properties Research Articles

Depth-Wise Distribution of Soil Chemical Properties, Micro-nutrients Status, and Bacterial Population under Quercus leucotrichophora and Shorea robusta Forest of Chakrata and Thano Region of Uttarakhand

Forest trees have an appreciable demand for nutrients as they have longer rotation than crops and this is easily replenished by the constant release of nutrients resulting from weathering under favorable conditions in the soils developed from parent material rich in nutrient-bearing minerals. A study was undertaken to assess the chemical properties, micro-nutrient status, and bacterial population; two sites were taken for the collection of soil samples: the oak forest of Chakrata and the Sal forest of Thano. Soils were drawn at three depths viz. 0-30 cm, 30-60 cm, 60-90 cm. All soil parameters examined at three depths viz. 0-30 cm, 30-60 cm, 60-90 cm. Oak (Quercus Leucotrichophora) forests have higher microbial activity than Sal forests. The soil in both the studied areas was rich in nutrients, where, the maximum mean standard deviation values of pH (6.85), soil organic carbon (5.9 %), available nitrogen (0.04 %) reported in the Oak forest of Chakrata, and available phosphorus were almost similar in both forest regions. Oak forests have higher organic carbon, water-holding capacity, and nutrient availability compared to Sal forests. However, it is concluded that, for better conditions of these forests for soil and carbon-storing potential, the forest needs good management practices, especially in community forest areas to avoid illegal felling, impact of fire, and over-exploitation of fuel and fodder. Good management practices would help mitigate the impact of climate change and sustainable outcomes of the resources for the community's benefit.

Distribution of Soil Chemical Properties of Smallholder Farms on Derelict Mined-Sites of Jos South LGA, Jos Plateau, Nigeria

Tin mining environments have constituted a degrading challenge to smallholder farmers whose lands have been overtaken. Attempts by smallholder farmers to restore the lands to farming are faced with soil productivity constraints. Yet, these farmers struggle to cultivate farms in-between the mined lands to meet up with subsistence food requirements. To date, the farmers have identified areas with low and high potentials due to years of continuous cultivation. This study was conducted in an environment that had undergone mining on a larger scale and is now undergoing surface mining on a small scale. Thirty-one (31) soil samples were taken at a depth of 0-20cm to investigate the spread of soil chemical properties on smallholder farms. Coordinates of the samples were acquired using GPS to create georeferenced continuous surfaces. The results indicated that the majority of the soil's chemical properties varied moderately. Organic matter (0.89-1.74%) and nitrogen (0.045 - 0.096%) needed mostly by crops were very low due to uninformed distribution of soil chemical properties. Geostatistics was used to generate continuous surfaces through Kriging. The small nugget effect showed spatial continuity between the neighboring points. Strong spatial dependence occurred for all soil nutrients tested, due to intrinsic soil properties such as soil parent material, topography, texture, and mineralogy. Generally, the spread of soil nutrients on the smallholder farm coincides with the smallholder farmers' identified potential areas. The study suggests that for proper nutrient interventions on the farms, distribution of soil nutrients on the farms should be done to avoid excesses and shortages of inorganic and organic interventions.

Vertical distribution of soil chemical properties under different land use systems of Biligirirangana Hills, Karnataka

Vertical distribution of soil chemical properties under different land use systems of Biligirirangana Hills, Karnataka

Temporal and Spatial Changes and Driving Forces of Soil Properties in Subtropical Mountainous Areas from 2017 to 2020: A Case Study of Baokang County, Hubei Province, China

Understanding the mechanism of regional soil chemical property changes is crucial for guiding precise farming and further alleviating poverty in mountainous areas. Our aims were to monitor the temporal and spatial changes in the soil chemical property in subtropical mountainous areas and explore the effect of human activities, soil and topographic factors on the changes. In this study, a total of 332 soil samples were collected from 2017 to 2020 in Baokang County, subtropical mountainous area in central China. We analyzed the soil pH, soil organic matter (OM), soil available phosphorus (AP), soil available potassium (AK), soil total nitrogen (TN) and used Kriging interpolation to draw the map of spatial distribution of soil chemical properties in Baokang County from 2017 to 2020. The geographical detector was used to explore the driving forces of soil chemical property change over the years of research. The results show that: 1) from 2017 to 2020, soil pH, soil OM, and soil AP in Baokang County was increasing from north to south and the value of three chemical properties showed a slight decreasing trend. Soil AK showed an increasing trend, with higher values in Longping and Xiema towns and relatively lower values in Guoduwan, and soil TN was at a high level with large spatial variation. 2) The human activities, soil and topographic factors all affect soil properties in Baokang. In human activities, the cropping system and crop yield were strong explanatory factors for the changes in soil chemical properties, especially for AK and AP. The q values of all the indicators in the soil factor were relatively high, which displays that all indicators we selected affected the changes in soil properties. Soil OM and soil TN were the factors that affected each other with the greatest driving force, as were soil AP and soil AK. The driving force of DEM was greater among the topographic factors (slope, topographic relief and DEM), and its effect on five soil chemical properties showed that AK>AP>OM>TN>pH. 3) The interactions between each two factors showed a two-factor-enhanced relation, indicating that multiple factors form the soil properties of Baokang County. The findings of this study offer some scientific basis and suggestions for local government to control soil quality and economic development.

Impact of Industrial Effluents on Spatial Distribution of Soil Chemical Properties In Gazipur

Rapid industrialization contributes to the rising economic growth rate in Bangladesh. Gazipur district is one of the largest industrial zones in Bangladesh. Every day a huge amount of untreated industrial effluents is produced and delivered to the nearby crop field or water body. These effluents might have influenced the major chemical properties of soils. Hence, the present study was conducted to assess the impact of untreated industrial effluents on soil chemical properties expressed through a spatial distribution pattern map of the industrial zone of Gazipur district. A total of one hundred and four agricultural soil samples were collected with grid basis from different unions of the industrial areas of Sreepur and Gazipur Sadar upazilas. In Sreepur upazila, the mean values of soil pH, organic carbon (OC), N, P, S, K, Ca and Mg were 4.85, 0.81%, 0.11%, 6.08 ppm, 26.5 ppm, 0.13 meq/100g soil, 0.53 meq/100g soil and 0.19 meq/100g soil, respectively in uncontaminated soil, while the mean values of soil pH, OC, N, P, S, K, Ca and Mg were 5.15, 1.96%, 0.23%, 14.2 ppm, 187.61 ppm, 0.15 meq/100g soil, 0.64 meq/100g soil and 0.2 meq/100g soil, respectively due to industrial contamination. In both the upazilas, soil pH was strongly to slightly acidic while soil organic carbon was low to medium and N content was low. A weak spatial variation was detected for soil pH and N in these industrial areas indicating less influence on both the parameters by the effluents. Similarly, the contents of K, Ca and Mg were low in most of the areas of these two upazilas and a very little or no spatial variation was observed. On the other hand, OC and P contents were low to medium whereas S content was high in most of the study areas. Ann. Bangladesh Agric. (2022) 26 (1) : 15-28

Spatial distribution of soil chemical properties in the cerrado of Tocantins

Information on spatial variability of soil chemical properties is allowing an increasingly efficient management of soil fertility. This study was conducted in the municipality of Santa Rosa do Tocantins, TO, in the 2018/2019 crop year. The objectives of the study were to characterize the spatial variability of chemical properties of a dystrophic Red Latosol in the Cerrado of Tocantins using geostatistics and optimize the management of soil fertility by means of precision agronomy techniques, for more efficient input use in agricultural production areas. For the experiment, 49 soil samples were collected at 0.2 m depth, from equidistant points in a regular grid 100 m apart, over an area of ??150 ha. Each sample was composed of 5 subsamples. The soil properties evaluated included pH, bases sum, potential acidity, organic matter, total cation exchange capacity, base saturation, phosphorus, sulfur, potassium, calcium, magnesium, boron, copper, iron, manganese, and zinc. A descriptive analysis was carried out, highlighting the mean, median, minimum, and maximum values for each soil variable. In addition, the coefficients of variation, asymmetry, kurtosis, and the normality test of Kolmogorov-Smirnov were performed. The area presented significant variations in chemical and macronutrient attributes and little variation in micronutrients, except for zinc. The study reveals variations in different soil attributes and the need for correction depending on the requirements of the crop.

Changes in soil bacterial communities with increasing distance from maize roots affected by ammonium and nitrate additions

It is well known that the interactive effect of nitrogen (N) fertilizer and plant root would cause distinct microbial communities and associations between root surface and bulk soil. However, little is known about the continuous changes of these microbial parameters along an increasing distance from roots under different N forms. Ammonium (NH4+) and nitrate (NO3−) are two major inorganic nitrogen (N) forms available for plant growth, and may have different effects on both plant growth and soil microbiome. Here, a rhizobox containing a root zone (root growing area) and various soil compartments (0–0.5 cm, 0.5–1 cm, 1–2 cm, 2–4 cm, and 4–9 cm from the root zone) was designed to investigate the spatial distribution of soil chemical properties, bacterial diversity, and community structure along a distance from maize (Zea mays L.) roots with the addition of 15N-labeled NH4+ or NO3− in an acidic red soil. Addition of NH4+ or NO3− reduced soil bacterial diversity only in the maize root zone. The structures of soil bacterial communities differed more significantly with addition of NH4+ or NO3− in the root zone and 0.5 cm away from the root zone compared with other soil compartments. Soil pH was the major driver of bacterial community assembly during plant uptake of N. Maize roots recruited acidophilic bacteria (e.g. Acidibacter, Burkholderia, and Catenulispora) under NH4+ treatment, and recruited bacteria that prefer higher pH (e.g. Sphingomonas, Sphingobium, Azospirillum, and Novosphingobium) under NO3− treatment. We concluded that the spatial patterns of soil bacterial communities at different distances from the maize root zone were influenced by the combined effects of the N form and rhizosphere, mainly as a result of changes in soil pH during the uptake of NH4+ and NO3− by maize roots.

ANALISIS DAN EVALUASI SIFAT KIMIA TANAH PADA LAHAN TEMBAKAU VARIETAS KEMLOKO DI SENTRA TEMBAKAU KABUPATEN TEMANGGUNG, JAWA TENGAH

This study aimed to analyze the effect of soil chemical consisting of pH, C-organic, CEC, and base saturation on the production and quality index of Kemloko tobacco varieties, and to identify distribution map of soil chemical properties. The study was conducted by field survey and analysis spatial was used Inverse Distance Weighted interpolation method. The results showed that distribution of soil chemical properties in Tobacco Centers at the Temangung Regency consisting of acidic pH value with a range of values 3,96-6,97, soil C-organic ranges low with a range of values 0,19-6,79%, soil CEC ranges from high to very high with a range of values 10,98-67,84 me/100g -1 , and low base saturation categories with a range of values 13,24-82,77%. Correlation coefficient obtained between the soil chemical properties and tobacco’s production; each of them is sequential, i.e., 0,112, -0,204, 0,005, -0,027 in the weak to very weak category. While the level of coefficient correlation between soil chemical properties and tobacco quality index, each of them is sequential, i.e. -0,001, -0,141, -0,175, 0,165 in the very weak category. This was because productivity and quality index of Kemloko tobacco varieties in Tobacco Centers at the Temanggung Regency on 2016 planted season due to high rainfall occurring throughout 2016 on the tobacco processing phase.

Soil acidification and P, K, Ca and Mg budget as affected by sheep grazing and crop rotation in a long-term integrated crop-livestock system in southern Brazil

The insertion of the animal component into the crop production system can alter the nutrient dynamics and, consequently, the soil fertility status over time. This change occurs differently according to the arrangement adopted, depending on both, the intensity and frequency of animal grazing, as well as the crop rotation system. This study was carried out aiming to evaluate the effect of sheep grazing intensity and frequency during the winter period and the crop rotation in the summer period on the (i) temporal evolution and vertical distribution of soil chemical properties, and (ii) on the nutrient (phosphorus – P, potassium – K, calcium – Ca, and magnesium – Mg) budget. The experiment was established in 2003, in a subtropical Acrisol in southern Brazil, arranged in a randomized block design with split plots. The treatments were two grazing intensities (moderate and low), two stocking methods (continuous and rotational), subdivided into two crop rotation systems (monoculture - soybean/soybean and crop rotation soybean/maize). Temporal variation of soil pH, exchangeable aluminum (Al), Ca and Mg, available P and K, base saturation, Al saturation, and cation exchange capacity (CEC) were evaluated in samples collected in 2003, 2010, 2015 and 2017, corresponding to 0, 7, 12 and 14-years after the beginning of the experiment. The vertical distribution (0–5, 5–10, 10–20, 20–30 and 30–40 cm) of these chemical properties were also evaluated 14-years after the beginning of the experiment (2017). The nutrient budget in the soil was calculated based on the initial and final available/exchangeable contents in the 0–10 cm soil layer and the inputs (fertilizers) and outputs (exportation by grain and meat) of nutrients. >95% of P, K, Ca and Mg were exported by grains and <5% by sheep meat. There was an intense acidification of the soil over the 14-years of experiment as shown by the decrease of soil pH and base saturation, and the increase of Al saturation. Crop rotation with soybean/maize increased CEC up to 5 cm soil depth and increased the available K content up to 40 cm soil depth. The available K budget was more negative in soybean monoculture due to higher grain exportation. Integrated crop-livestock system involving low grazing intensities and rotational stocking methods, coupled with crop rotation in the summer, was more efficient in the use of nutrients.

Spatial distribution of soil chemical properties in an organic farm in Croatia.

Soil pH, electrical conductivity (EC), organic matter (OM), available phosphorus (AP), and potassium (AK) are some of the most important indicators of soil fertility. These soil parameters are highly variable in space and time, especially in agricultural areas, with implications for crop production. The aim of this work was to study the spatial variability of pH, EC, OM, AP and AK using kriging and co-kriging methods in the Rasa River Valley (Croatia). As co-variates for each variable we considered the distance from the sea (DFS), distance from the river channels (DFC), pH, EC, OM, AP and AK. Only the variables with a significant correlation with the predictor were used as predictor variables. The results showed that soils of the study area had high pH, EC, OM and AK values and a low concentration of AP. The spatial variability was high for EC and low for pH levels. pH, EC, OM and AK had significant positive correlations. All these variables had significant negative correlations with AP. The exponential model was the best to model OM, AK and AP. Spherical and Gaussian models were the most accurate to model pH and EC. Spatial dependence was high for soil AK, EC and pH, and moderate for soil OM and AP. The incorporation of auxiliary variables increased the precision of the estimations. CoK_DFS was the best method to predict soil EC and AP, while Cok_EC, was better to estimate soil pH and Cok_pH and Cok_OM predicted soil OM and AK with the best accuracy. The maps produced with the best predictors showed that pH, EC, OM and AK had high levels in the northern and eastern parts of the study area. The opposite trend was identified in relation to the AP spatial pattern.

English

The aim of this paper was to quantify and evaluate the spatial distribution of soil chemical properties in different grid sampling sizes using descriptive statistics and geostatistics. The study was carried out in Bom Sucesso City, Paran&aacute; State, Brazil. Using GPS, a 50 x 50 m grid sampling size was set, comprising four samples per hectare. In each grid point positioned on the field, soil samples at a depth of 00 to 0.20m were extracted, resulting in 203 sampling points in a 51.15 ha area. Calcium, magnesium and potassium quantity were determined. Grid sampling size, with lower number of samples per area, were established from the first grid, removing randomly, soil samples, resulting in: 70.8 x 70.8 m (2 samples/ha), 100 x 100 m (1 sample/ha), 141 4 x 141.4 m (1 sample/2 ha), 173.3 x 173.3 m (1 sample/3 ha) and 200 x 200 m (1 sample/4 ha) grid sampling sizes. Each soil chemical properties in each grid sampling size were subjected to descriptive statistical and geostatistical analysis. An experimental semivariogram was developed to understand the spatial dependence structure. The attributes calcium, magnesium and potassium showed spatial correlation in almost all grids sampling, except for the 200 m grid sampling for calcium and magnesium. &nbsp; Key words: Spatial distribution of attributes, spatial dependence, descriptive statistics, geostatistics.

DISTRIBUIÇÃO ESPACIAL DAS PROPRIEDADES DO SOLO, PRODUÇÃO

A existência de variabilidade espacial nas propriedades do solo influencia na produção da forrageira. O trabalho teve como objetivo determinar a distribuição espacial das propriedades químicas do solo relacionando-a com a produção e a preferência de forragem por animais em pastejo de Urochloa brizantha cv. Marandu (Syn. Brachiaria brizantha) sob lotação contínua. Para caracterização da área de pastagem, foram realizadas medições de 108 pontos com distribuição em malha irregular, com coletas de solo para determinação dos atributos químicos (pH, matéria orgânica, P, K, Ca, Mg, Al, H+Al) e densidade do solo, produção de forragem, altura do dossel forrageiro, índice SPAD e intensidade de pastejo, no período das águas de 2012. Realizou-se o teste de normalidade, seguido de análise descritiva dos dados e análise geoestatística. As características químicas e densidade do solo, bem como a produção e altura do pasto, apresentaram dependência espacial, com mesmo padrão de resposta, inferindo que tais respostas são interrelacionadas. Os fatores que causam a variabilidade nas características do solo também interferem nas relacionadas ao pasto influenciando em parte no pastejo animal. Os atributos químicos do solo, densidade, massa seca, altura e intensidade de pastejo, ajustaram-se ao modelo exponencial. A estimativa da variabilidade espacial dos atributos do solo juntamente com avaliação da disponibilidade do pasto e os pontos de preferência do pastejo animal são ferramentas importantes para estabelecer critérios de uso e manejo diferenciado dentro de uma mesma área de pastagem, na perspectiva de evitar degradação do solo e do pasto.

Spatial and Fractal Characterization of Soil Chemical Properties and Nutrients across Depths in a Clay-Loam Soil

Researchers assessed the spatial distribution of soil chemical properties and nutrients at four depths in a clay loam soil cropped to corn and soybean at Freeman farm of Lincoln University. Soil samples were taken at depths of 0–10, 10–20, 20–40, and 40–60 cm in a 4.05-ha field and analyzed for acidity or basicity (pH), cation exchange capacity (CEC), total carbon (TC), organic matter (OM), base saturations on the CEC, ammonium (NH4+), nitrate (NO3−), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), sodium (Na), manganese (Mn), copper (Cu), iron (Fe), and zinc (Zn). Results showed that coefficients of variation (CV) ranged between 5 and 30%, except for TC, NO3−, and Zn, which had greater CVs. Soil chemical properties and nutrients responded to exponential, linear, Gaussian, and spherical variogram models with nugget-to-sill ratios ≤ 1.0 and effective ranges from 4 to 56 m. Fractal analysis showed that CEC in all depths belonged to the 1.99 ≥ D3 ≥ 1.90 group, which suggests great disorder and antipersistence in the spatial structure.

Distribuição espacial de atributos químicos do solo em área de pastagem e floresta

O conhecimento da distribuição espacial de atributos do solo, por meio da geoestatística, é importante como indicador para um melhor uso e manejo do solo. Este estudo objetivou avaliar a distribuição espacial de atributos químicos do solo, em área de pastagem e floresta, na região de Manicoré (AM). Foram estabelecidas malhas de 70,00 m x 70,00 m, com espaçamento regular de 10,00 m x 10,00 m, totalizando 64 pontos, e, em seguida, coletadas amostras de solo, às profundidades de 0,0-0,20 m e 0,40-0,60 m, sendo determinados os seus atributos químicos. Os dados foram analisados utilizando-se técnicas de estatística descritiva e geoestatística, e a densidade amostral determinada com base no coeficiente de variação e no alcance dos semivariogramas. Os valores da média e mediana se ajustaram aos valores próximos, indicando distribuição normal, enquanto os modelos esférico, exponencial e gaussiano se ajustaram aos atributos químicos do solo. Concluiu-se que a geoestatística forneceu informações adequadas para a compreensão da distribuição espacial. A área com floresta apresentou maior continuidade espacial e a área com pastagem menor densidade amostral. Os atributos químicos evidenciaram diferenças na variabilidade espacial, enquanto o alcance representou melhor as estimativas para a densidade amostral e espaçamento, na área de floresta e pastagem.

One‐Time Tillage of No‐Till: Effects on Nutrients, Mycorrhizae, and Phosphorus Uptake

Stratification of nutrient availability, especially of P, that develops with continuous no‐till (NT) can affect runoff nutrient concentration and possibly nutrient uptake. The effects of composted manure application and one‐time tillage of NT on the distribution of soil chemical properties, root colonization by arbuscular mycorrhizae (AM), and plant P uptake were determined. Research was conducted on Typic Argiudoll and Mollic Hapludalf soils under rainfed corn (Zea mays L.) or sorghum [Sorghum bicolor (L.) Moench.] rotated with soybean [Glycine max (L.) Merr.] in eastern Nebraska. Tillage treatments included NT, disk, chisel, moldboard plow (MP), and mini‐moldboard plow (MMP). Subplots had either 0 or 87.4 kg P ha−1 applied in compost before tillage. Bray‐P1 was five to 21 times as high for the 0‐ to 5‐cm as compared with the 10‐ to 20‐cm soil depth. Greater redistribution of nutrients and incorporation of compost P resulted from MP tillage than from other tillage treatments. One‐time chisel or disk tillage did not effectively redistribute nutrients while MMP tillage had an intermediate effect. Compost application reduced AM colonization of roots at R6 for all crops. Tillage reduced AM colonization with reductions at R6 due to MP tillage of 58 to 87%. The tillage effect on colonization persisted through the second year with no indication of AM recovery. Root P concentration was increased by MP and was negatively correlated to colonization. Decreased colonization did not result in decreased plant P uptake. Infrequent MP tillage can reduce surface soil P and the potential for P loss in runoff, but may reduce AM colonization of the roots, possibly reducing P uptake with some low P soils. The results do not indicate any advantage to one‐time tillage of NT if runoff P loss is not a concern.

The effects of landscape attributes and plant community on soil chemical properties in rangelands

This study addressed the effect of landscape attributes and plant community type on the spatial distribution of soil chemical properties in an alpine rangeland in a semiarid area of Iran. To identify the effects of landscape attributes on soil chemical properties, the present study collected and analyzed information from air photos, satellite images, field survey, and the laboratory using statistical analyses. Land stratification allowed the study area to be subdivided into Land Unit Tracts (LUT), according to specified criteria including landform attributes (slope, aspect, and altitude), and vegetation type. A factorial model on the basis of a completely randomized design was used to analyze the data collected from 234 LUT. The interrelationships between soil chemical properties and landscape attributes were investigated and interpreted based on statistical analysis and expert knowledge. Most chemical properties of the 0- to 10-cm topsoil including EC, OC%, total N%, P, and K significantly related to slope gradient. Soil chemical properties including the grouping described as nutrient elements (CEC, N, P, K, and OC), and pH significantly related to aspect of slope. In addition lower soil temperature and less moisture evaporation on a north-facing slope (shady aspect) resulted in less organic matter decomposition and consequently more organic carbon and total nitrogen accumulation in the soil. Consequently, the soil nutrient pool and general fertility on north-facing slopes was greater than on south-facing slopes. The interdependency of landscape attributes, plant community, and soil chemical properties led to a variety of species, vegetation types, and plant communities existing in the study area. In this research, vegetation type was highly significantly related to all the determined soil chemical properties except for cation exchange capacity.

Drainage Network Analysis for Regional Partitions of Alluvial Paddy‐Field Soils

Terrain data on floodplains might be a useful source of ancillary information about soil properties at a regional scale. However, terrain data are not believed to be suitable for obtaining information on paddy‐field soils on floodplains, because the contrast in the topography of floodplains is only slight. This study was conducted in the Tsuruoka area, a part of the Shonai Plain in the northern part of Japan, to evaluate whether a division of floodplain into landform elements can provide useful information on delineation of paddy‐field soils. As source data for the division, a digital elevation model (DEM) was constructed based on a closely spaced differential global positioning system (DGPS) survey and geostatistical interpolation. By using the DEM, drainage network analysis was performed to delineate the landform units. To evaluate correspondence of soil classification with the land division, soil chemical data from 154 soil samples were classified by using a set of numerical procedures. The numerical procedures included principal component analysis and unsupervised classification techniques. In the land partition map created, each landform unit could satisfactorily represent a separate soil group as characterized by soil chemical properties. A statistical analysis revealed that the regional partition map was better than the conventional soil map inasmuch as the partition map described more satisfactorily the spatial distribution of soil chemical properties. However, this conclusion depends largely on the spatial resolution and precision of the DEM. The useful regional partition map could not be produced by different DEM that has lower resolution and accuracy.

Soil chemical properties as influenced by tillage and nitrogen source, placement, and rates after 10 years of continuous sorghum

Tillage and nitrogen (N) management practices can have profound effects on the variations in plant nutrients and other soil chemical properties with depth in the soil. Relatively few studies have reported on such effects with grain sorghum ( Sorghum bicolor (L.) Moench) compared to crops such as corn ( Zea mays L.). These changes can influence crop yields, nutrient utilization, and soil and water quality. The purpose of this study was to determine the effects of tillage and N management practices on selected soil chemical properties with depth after 10 years of grain sorghum production under no-till (NT) and chisel-disk (CD) systems. Ammonium nitrate and urea ammonium nitrate (UAN) solution were evaluated at 34, 67, and 135 kg N/ha. The UAN solution was applied either broadcast on the soil surface or knifed below the soil surface and ammonium nitrate was broadcast on the soil surface. Soil samples were collected from 0 to 15 cm by 2.5 cm increments, 15–30 cm by 5 cm increments, and from 30 to 40 cm. Soil pH decreased in the upper 5 cm of soil for NT with increasing N rates from surface broadcast applications of ammonium nitrate or UAN solution with no such effects for subsurface placement of UAN. The largest decrease was from 6.7 to 5.2 at 0–2.5 cm for ammonium nitrate. For CD treatments receiving 135 kg N/ha, soil pH was significantly lower in the upper 10 cm compared to treatments receiving ≤67 kg N/ha. The lowest pH found at the soil surface for NT was 5.2 compared to 5.8 for CD. Extractable P was significantly higher for NT compared to CD at 0–2.5 and 2.5–5.0 cm while similar results were obtained for extractable Ca down to 10 cm. Extractable K was not influenced by tillage, but extractable Mg was higher for CD compared to NT below 15 cm. For NT, organic carbon (C) concentrations were higher near the soil surface compared to CT and increased with increasing N rates. The largest increases were seen at 0–2.5 cm for broadcast ammonium nitrate where organic C increased from 14.5 to 19.2 g/kg. Organic C concentrations were higher for treatments receiving N than for the controls with CD. This study demonstrates that tillage and N source, placement and rate can influence the distribution of soil chemical properties with depth.