Sustainable Soil Fertility Research Articles

Long-Term Effects of Calcium-Based Liming Materials on Soil Fertility Sustainability and Rye Production as Soil Quality Indicators on a Typic Palexerult

Liming is a common practice used to improve acidic soil properties, as is essential for agricultural quality. A long-term field experiment with one lime rate (6000 kg/ha of carbonate calcium equivalent) and three calcium-based liming amendments (gypsum, limestone and sugar foam) was maintained on a Typic Palexerult for 10 years in order to determine changes in soil acidity and to assess the effects on crop (rye) yields. The soil acidity conditions decreased with all the amendments tested, but the sugar foam and limestone was more effective than gypsum over a long-term period. No significant changes in organic soil matter levels between the treatments tested were found. Interestingly, an increase in the leaching of organic soil matter was observed in limed soils. Lime application significantly increased the total rye biomass compared to the control soils during the whole experiment (2002–2011). Yield trends observed in spike and stem biomass were similar to those reported for total rye biomass. In this respect, at the end of the research, gypsum, limestone and sugar foam increased in relation to the total production of rye biomass by 16%, 32% and 38%, respectively, as compared to the control soils. Additionally, a significant and prolonged difference in calcium concentrations in rye stems between unlimed and limed subplots was observed. However, in spite of the results presented here, further investigations are needed to gain a better understanding of the long-term effects of liming on the chemical properties of soil.

Estimating Soil Loss for Sustainable Crop Production in the Semi-deciduous Forest Zone of Ghana

Quantitative information on soil loss is relevant for devising soil conservation and crop management strategies to ensure sustainable fertility management and crop production. Estimations from runoff/erosion plots are expensive and laborious and thus requiring the exploration of other less expensive but reliable methods such as modeling. This study aimed to estimate current and future rates of soil loss for conservation planning toward sustainable crop production in the semi-deciduous forest zone of Ghana. The Universal Soil Loss Equation (USLE), which took into consideration the rainfall characteristics of the study area, inherent soil physicochemical and hydraulic properties, variations in slopes and terrain differences, land cover types, and soil management practices, was employed to estimate the magnitude and rate of soil loss in the study area. Output from three regional climate models (RCMs) from Coordinated Regional Climate Downscaling Experiment including CCCma-CanESM2, GFDL-ESM2M, and HadGEM2-ES were used to estimate the impact of climate change on soil erosion in the study area. The results showed that soil loss estimated for bare soils was high ranging from 12.7 to 163.8 t ha−1 year−1 largely due to variation in slopes coupled with soil physicochemical and hydraulic properties. The simulated annual soil losses under various land cover options showed variable degrees of soil loss for maize cultivation under conventional tillage (8.2–106.5 t ha−1 year−1), soya bean monocropping (4.4–57.3 t ha−1 year−1), and low soil loss for oil palm plantation with grass or leguminous cover (2.5–32.8 t ha−1 year−1). Evaluation of the RCMs showed excellent performance for CCCma-CanESM2 and GFDL-ESM2M. Predictions of climate change impact using outputs from CCCma-CanESM2 and GFDL-ESM2M indicated that 9–39% increase in soil loss is expected by 2070, and it will be more severe (16–42%) by 2100. The model predictions indicate that the adoption of site-specific land cover management strategies such as tree–cover crop intercropping and reduced tillage has a huge potential to reduce soil loss and sustain soil fertility. The model can be used as an advisory tool for mapping areas for appropriate cropping systems for a particular site.

Evaluation of the Regional-Scale Optimal K Rate Based on Sustainable Apple Yield and High-Efficiency K Use in Loess Plateau and Bohai Bay of China: A Meta-Analysis

In order to meet the growing food demand of the global population and maintain sustainable soil fertility, there is an urgent need to optimize fertilizer application amount in agricultural production practices. Most of the existing studies on the optimal K rates for apple orchards were based on case studies and lack information on optimizing K-fertilizer management on a regional scale. Here, we used the method of combining meta-analysis with the K application rate-yield relationship model to quantify and summarize the optimal K rates of the Loess Plateau and Bohai Bay regions in China. We built a dataset based on 159 observations obtained from 18 peer-reviewed literature studies distributed in 15 different research sites and evaluated the regional-scale optimal K rates for apple production. The results showed that the linear plus platform model was more suitable for estimating the regional-scale optimal K rates, which were 208.33 and 176.61 kg K ha−1 for the Loess Plateau and Bohai Bay regions of China, respectively. Compared with high K application rates, the optimal K rates increased K use efficiency by 45.88–68.57%, with almost no yield losses. The optimal K rates also enhanced the yield by 6.30% compared with the low K application rates.

A review of the Current State of Soil Infertility and Management Options in Kenya: The Case of Maize Growing Regions

Inappropriate soil fertility management has caused fertility to decline considerably over the years leading to low maize yields despite the growing human population with high food demand in Kenya. Despite high nutrient mining, fertilizer use and adoption of soil fertility improvement practices have remained low among maize farmers in the country. At the current yield levels, maize crops extract over 40, 8, 40.6, and 5.4 kg of N, P, K, and S per growing season, respectively. These extracted nutrients must be replaced to avoid nutrient depletion. Maize crop response to secondary macronutrients (S, Ca, and Mg) and micronutrients (Zn and B) is evidenced, signifying that these nutrients have also reached critical levels in Kenya soils. The rate of replenishing these lost nutrients is still low, farmers apply an average of 43.25 kg of fertilizer per hectare per season. The situation is worsened further by increasing soil acidity- currently below pH 5.5 in most maize-growing regions. Poor agronomic practices applied by farmers directly reduce yields and facilitate other factors leading to nutrient losses. For example, farmers across the country recycle seeds, apply low fertility rates, and rarely keep their fields weed-free. These practices lower the capacity of the crops to tolerate the impact of other production constraints including infertility. To realize yield improvement and return on investments, farmers must adapt and adopt crucial practices under integrated soil fertility management. Managing soil acidity should be the first approach to unlocking fixed nutrients. Fertilizer application should follow the right rate, right source, right time, and right placement approach. Also, improved cropping systems such as maize-legume rotation and intercropping should be considered for sustainable soil fertility management and crop production.

Soil management practices in commercial vegetable farming in changing socioeconomic context in Makawanpur, Nepal

With the rapid urbanization and population growth, the demand for vegetables is increasing day by day resulting in increased cultivation area and production at the expenses of soil fertility. This study aims to assess soil management practices adopted by commercial vegetable farmers in changing socioeconomic contexts in Bhundrung village, Makawanpur. Participatory rural appraisal tools; Household Questionnaire survey, Focus group discussion, Key informant interview and expert consultation were used for data collection. Most farmers use farmyard manure (FYM) and chemical fertilizer (urea, potash and di-ammonium phosphate) for maintaining soil fertility. Application of farmyard manure is decreasing, due to large farm size but less number of livestock. It has resulted in the scenario of injudicious supply of chemical fertilizers with hope of increment in production. Lack of knowledge on dose, handling and disposal of fertilizer and pesticides threatened degradation of soil and water quality in and outside the farm. In the changing socioeconomic context, farmers practice joint decision making in laborious activities like nursery bed preparation, field preparation, manure mixing, intercultural operation whereas in technology and direct money related activities were decided by male members. This study recommends there is a need for effective extension services for sustainable soil fertility management, finance and market access for economic benefits and gender friendly environment and technology for commercial vegetable farming.

After-effects of straw and straw-derived biochar application on crop growth, yield, and soil properties in wheat (Triticum aestivum L.) -maize (Zea mays L.) rotations: A four-year field experiment.

Research on the after-effects of straw and straw-derived biochar applications on crop growth, yield, and retention of carbon (C) and nitrogen (N) in soil in wheat-maize rotation systems is limited, and has presented inconsistent conclusions. The purpose of this research was to compare the after-effects of straw and straw-derived biochar on wheat (Triticum aestivum L.) and maize (Zea mays L.) growth and yield, and on soil properties. A field experiment was conducted in four consecutive wheat-maize rotation cycles in the Loess Plateau of China under five treatments: CK (control without nitrogen and phosphate fertilizer, straw, or biochar); NP (conventional single application of nitrogen and phosphate chemical fertilizers); SNP (8tha-1 wheat straw returned to the field plus fertilizer); B1NP (8tha-1 straw-derived biochar plus fertilizer); B2NP (16tha-1 straw-derived biochar plus fertilizer). The highest plant height and aboveground biomass for both wheat and maize always occurred with the B2NP treatment for the four study years. Grains per spike/ear and 1000-grain weight for both wheat and maize in B2NP and B1NP were significantly higher than observed for the other treatments. The four-year average wheat yields for NP, SNP, B1NP, and B2NP were 50.5%, 63.1%, 66.3%, and 81.7% greater than for CK, respectively, and the four-year average maize yields were 45.0%, 49.8%, 65.4%, and 72.1% greater than for CK, respectively. The application of straw-derived biochar significantly increased soil organic carbon, total nitrogen, microbial biomass carbon, and nitrogen in the soil surface layer compared with returning straw to the field. Both straw and straw-derived biochar reduced nitrate N leaching. Therefore, using straw-derived biochar to amend soil could be an appropriate practice for sustaining soil fertility and crop yield in wheat-maize rotation systems in the Loess Plateau of China.

Sugarcane bagasse biochar increases soil carbon sequestration and yields of maize and groundnut in charland ecosystem

ABSTRACT Charland is newly developed land in river beds which is poor in fertility. Sugarcane bagasse (SB) biochar was produced and characterized, and its performances were evaluated on carbon sequestration and yields of maize and groundnut in charland. The bagasse after pyrolysis ≈ at 600°C temperature produced 55% biochar. The pH value increased from 6.5 (SB) to 8.8 (biochar), C from 42% to 58%, P from 0.11% to 0.23%, K from 0.83% to 1.32% and the S content from 0.12% to 0.61%; whereas the N content decreased from 2.03% to 1.17%. Seven treatments were implemented in field trials of 2016–17 and 2017–18 in Brahmaputra charland consisting of control, 100% chemical fertilizers (CF), CF+ Cowdung (10 t ha−1), CF+ biochar (5 t ha−1 broadcast), CF + biochar (10 t ha−1 broadcast), CF+ biochar (5 t ha−1 furrow application) and CF+ biochar (10 t ha−1 furrow application). Amendment was done in the year one. Results reveal that the same dose of cowdung or biochar with CF produced higher grain yields of maize and groundnut with 40–60% increase over sole CF treatment. Integrated use of 10 t ha−1 biochar with CF can ensure higher crop yield and sustained soil fertility in charland ecosystem.

Abundance, biomass and community composition of soil saprophagous macrofauna in conventional and organic sugarcane fields

Tropical island saprophagous invertebrates have received little attention despite their important role in sustaining soil fertility. Soil biodiversity in the agroecosystems of the Lesser Antilles is subject to various anthropic and environmental perturbations; therefore, it is crucial to promote agricultural practices that help preserve it. Here, we investigate the effect of conversion to organic farming in sugarcane production on soil saprophagous invertebrates in a Martinique plantation (Lesser Antilles). The abundance, biomass and diversity of communities were measured in three fields undergoing organic conversion and in two control fields under conventional production. Invertebrates were sampled both by pitfall trapping and Tullgren extraction. The results indicated that abundance was significantly higher in fields undergoing conversion (342 ± 78 ind.m−2) compared to fields under conventional farming (146 ± 34 ind.m−2). The response of the whole community's biomass to organic conversion was not significant, reflecting a contrasting response of each invertebrate taxa: isopod biomass was the most impacted, earthworm biomass was moderately impacted and diplopod biomass was not significantly affected. A total of 25 morphospecies for all taxa were distinguished in this study. However, the diversity did not differ and community composition remained similar under both farming practices. The response of invertebrate abundance and biomass could be either due to the direct toxicity of herbicides intensively used in conventional sugarcane cultivation or to the indirect effects of herbicides modifying micro-habitat parameters (weed biomass, amount of mulch and litter humidity). In conclusion, the study shows that organic farming has a beneficial effect on soil saprophagous invertebrates even after a short period of conversion (between one and two years), which is promising for restoring soil biological processes in the context of agroecological transition.

Light conditions and mulch modulates the damask rose (Rosa damascena Mill.) yield, quality, and soil environment under mid hill conditions of the western Himalaya

Damask rose (Rosa damascena Mill.) is an important aromatic crop used in the flavor, fragrance, and pharmaceutical industries worldwide. The environmental and health problems related to chemicals have contributed to a rise in environmentally friendly practices. Microclimate modification usually guarantees sustainable crop and higher productivity; however, this does not always happen. A two-year field study with three shade levels (control, 25 % shade, and 50 % shade) and three types of mulches (without mulch, organic mulch, and black polyethylene mulch) was conducted during 2016−17 and 2017−18 in a split-plot design. Yield attributes and yield of damask rose were significantly higher in black polyethylene mulch under open sunny conditions (control). Moisture content and soil nutrients viz., available N, P, K were maximum in black polyethylene mulch under 50 % shade level. The relationship between photosynthetic active radiation, soil and air temperature, and microbial community with fresh flower yield revealed that with the increase in solar radiations, soil and air temperature increases the microbial population, which ultimately increased the fresh flower yield and essential oil yield. A positive and significant correlation between soil nutrient status and fresh flower yield was recorded. Our finding demonstrated that the combined application of appropriate light intensity and mulch could be considered for sustaining soil fertility and enhancing the damask rose crop's productivity. It can be recommended to farmers and industrialists as an alternative, sustainable, and cleaner cultural system under the western Himalayas conditions.

Quanti-Qualitative Response of Swiss Chard (Beta vulgaris L. var. cycla) to Soil Amendment with Biochar-Compost Mixtures

In recent years, soil addition with organic amendments, such as biochar and compost, has gained attention as an effective agronomic practice to sustain soil fertility, enhance plant growth and crop yield. Well known are the positive effects of compost on yield of a wide crop varieties, while both positive and negative responses are reported for biochar Therefore, the aim of the study was to verify the effect of biochar mixed with three types of compost on quanti-qualitative response of Swiss chard (Beta vulgaris L. cycla), a leafy green vegetable rich in dietary antioxidants, largely consumed worldwide. A factorial experiment in pots with two factors, including biochar (without biochar and with biochar from vine pruning residues) and compost (without compost, with compost from olive pomace, with vermicompost from cattle manure, and with compost from cattle anaerobic digestate), was setup. Two growth cycles were considered, and a set of quantitative (height of plants, number, area and fresh weight of leaves) and qualitative parameters (carotenoids, chlorophyll, total N, and NO3−content of leaves) were analyzed. Biochar decreased plant growth and NO3− leaf content; on the contrary, it increased total N leaf content, while compost improved all the considered parameters. The interactive effect of biochar and compost was evident only on total N and NO3− leaf content. In our experimental conditions, the compost showed to be the best option to improve Swiss chard growth and increase the content of phytopigments, while the biochar-compost mixtures did not produce the expected effect.

Effect of Seedlings Age and Nutrient Combinations on Growth and Yield of Proso Millet (Panicum miliaceum L.) in Lateritic Soils of Western Ghats

Background: Proso millet (Panicum miliaceum L.) was considered a self-pollinated annual crop that belongs to the family Poaceae. It was well adapted to many soil and climatic conditions. The productivity was low due to the use of poor quality seed, little or no use of fertilizers, traditional methods of cultivation, delay in nursery sowing and late transplanting. The Integrated Nutrient Supply System (INSS) approach involves the combined use of chemical fertilizers, organic manures and micronutrient fertilizers, which ensures higher crop productions and also helps to restore and sustain soil fertility. Therefore, the study was focused to manage the timely transplanting together with the suitable nutrient combination.Methods: A field experiment was conducted to study the “Effect of seedlings age and different nutrient combinations on growth and yield of Proso Millet (Panicum miliaceum L.) in lateritic soils of Western Ghats” during Kharif, 2016. The experiment was laid out in a split-plot design with four main plots and five subplot treatments. The main plot treatments composed of four ages of seedlings viz. 20, 30, 40 and 50 days. and five subplot treatments of nutrient combinations viz., 100% RDF, 75% RDF + 25% N through FYM, 50% RDF + 50% N through FYM, 25% RDF + 75% N through FYM and 100% N through FYM. Thus, there were twenty treatment combinations, replicated thrice.Result: Results revealed that the proso millet crop transplanted with 30 days old seedlings recorded significantly higher grain yield and straw yield over all other treatments. In nutrient combinations treatments, 100% RDF through chemical fertilizer recorded significantly higher mean plant height hill-1, number of functional leaves hill-1, number of functional tillers hill-1 and plant dry matter accumulation hill-1 than the other treatments and also produced significantly highest yields and yield attributing characters compared to the rest of the nutrient combinations.

Review on Organic Fertilizer and Its Roles in Sustaining Soil Fertility in Ethiopia

Organic fertilizers increase the quality and yield of agricultural crops in ways similar to inorganic fertilizers. As the price of synthetic fertilizers continues to increase, manure is becoming a more valuable and less expensive source of nitrogen fertilizer. Crop producers are increasingly buying manure from livestock producers or adding livestock to their crop operations so that they can incorporate manure into their practices. On-manufactured nitrogen fertilizers are increasingly being used as a means to reduce vulnerability to the price changes in fossil fuels. The most common alternatives to non manufactured nitrogen fertilizers identified include green manures and integrating livestock into crop production. These practices, combined with other techniques such as conservation tillage, have shown to greatly decrease the need for synthetic fertilizers by increasing nutrient efficiency and improving soil health. Organic nutrient source improves the physical, chemical and biological quality of soil besides providing both macro and micro nutrients to crops. The improvement in qualities include improvement in soil structure, water holding capacity, electrical conductivity, bulk density, lesser soil erosion, preventing the leaching of nutrients and provide nutrients to soil micro flora. Keywords : Compost, Organic fertilizer; Vermicompost DOI: 10.7176/JNSR/12-4-02 Publication date: February 28 th 2021

Biochar and leguminous cover crops as an alternative to summer fallowing for soil organic carbon and nutrient management in the wheat-maize-wheat cropping system under semiarid climate

Cereal-based cropping systems under arid and semiarid climates have typically low soil organic matter and fertility, and natural fallowing during summer gap could have negative effects on soil quality and health. We tested an alternative approach of using biochar and leguminous cover crops to replace natural summer fallowing of about 75 days in the wheat-maize-wheat cropping systems with a view of studying the effects on legume productivity, soil organic carbon (C), and soil nutrients over the 2-year experiments. The two-factor completely randomized block experimental design consisted of biochar, developed from acacia tree biowaste and applied at 0, 5, and 10 t ha−1 rate, and leguminous cover crops (cowpea, mungbean, and sesbania) with natural fallow were used to test soil fertility and crop productivity. Treatments were laid out following completely randomized block design and each treatment had three replicates leading to 36 experimental plots in total. Pearson’s correlation coefficients were calculated to find the relationships between plant and soil variables. Regression analysis was performed to study correlations of total organic C with soil available N, P, and K contents. Results from the 2-year experiment indicated that plant height, pods plant−1, grains pod−1, 1000-grain weight, fresh and dry biomass, and grain yield were higher at 10 t ha−1 biochar rate; however, the nodule density plant−1 of cowpea and sesbania was the highest at 5 t ha−1 biochar. Integrating legumes with biochar further conserved and improved soil C which significantly positively correlated with soil fertility indicators. Despite linear positive changes in soil pH and electrical conductivity (EC) with biochar rate, increase was minor and was never significant. We observed significant positive relationships of biochar rate with soil organic C contents and soil N and K contents whereas soil P contents were higher at 5 t ha−1 biochar rate. However, not always significant difference between 5 and 10 t ha−1 biochar rates for legume and soil productivity suggested flexibility of choosing the biochar application rate. Our study emphasized that adopting integrative biochar-leguminous cover crop fallowing to replace natural summer fallowing could yield beneficial effects in terms of conserving soil organic carbon, sustaining soil fertility, and improving soil quality. In addition to positive supplementary effects on the succeeding crops, this approach also allows at utilizing and recycling on-farm biowaste more efficiently and environment friendly.

Production and Characterization of Crop Residues Derived Biochars for Soil Amendment and Carbon Sequestration

This study focused on the production and characterization of biochars from three types of crop residues comprising cotton stems, corn cobs and sorghum stems. The reactor used was a local cone kiln made from a 200-liter drum. The production parameters measured included the duration of pyrolysis, the amount of biochar produced and the production yield. The chemical characteristics of the biochars were determined using the usual analytical methods used for organic amendment analyses. According to the study, pyrolysis time, biochar quantities and production yields depended on the type of crop residues. The three types of biochar obtained showed high C/N values indicating that their use as soil amendment must be combined with mineral fertilizers to ensure good plant development and crop yield. The heavy metal contents of the three biochar types complied with the international standards recommended for biochars by the International Biochar Initiative (IBI) and by the European Biochar Certificate (EBC). The production and the use of Biochar from crop residues is an interesting alternative for sustainable soil fertility management in the Sahelian countries.

Impact of environmental factors on the spatiotemporal variability of soil organic matter: a case study in a typical small Mollisol watershed of Northeast China

Soil organic matter (SOM) content is one critical indicator of agricultural sustainability. Analyzing the spatial distribution and temporal variation of SOM content and its influencing factors at the watershed scale is essential for maintain sustainable soil fertility and productivity in the Chinese Mollisol region. A total of 292 soil samples at the same sampling points in 2005 and 2016 were used to quantitatively study the spatial heterogeneity of SOM dynamics in Tongshuang small watershed. Effects of land use types and topographic factors (slope gradient, slope positions, slope aspect, elevations, and topography wetness index (TWI)) on the spatiotemporal distribution of SOM dynamics were investigated. The results showed that the variability of SOM content was moderate variation, with an increase rate of 0.21 g kg−1 year−1 from 2005 to 2016. The spatial autocorrelation of SOM content was strengthened by 30.37% in 2016 compared with that in 2005. Slope gradient, slope position, slope aspect, elevations, and TWI had significant effects on the SOM content in 2005 and 2016, but not for the variation of SOM content. The explanatory ability of each factor and their interaction to spatial variability of SOM content was strengthened from 2005 to 2016. Slope gradient and TWI could explain over 8.15% of spatial variability in SOM content. A combination of slope position with TWI was the dominant interaction factor that explaining at least 16.0% of the SOM distribution. This study is important for the accurate estimation of carbon reserves, sustainable utilization, and management of soil nutrients and to improve soil productivity in the Chinese Mollisol region.

Characterization and Classification of Soils of Askate Sub-watershed, Northeastern Ethiopia

Characterization and classification of soil is the main central information source for judicious soil management and enhance agricultural economy. Therefore, this study was conducted with the objective of characterization and classification of soil on Askate sub-watershed, northeastern Ethiopia. Four representative soil pedons were opened along topographic position and described on each identified genetic horizons basis on the field for their morphological characteristics following the soil field description guidelines. The morphological properties were examined in the field while physical and chemical properties were analyzed in laboratory. The results of the study were revealed variation in morphological, physical, and chemical properties of the soils. Soil textural classes were sandy loam to loam sandy. The bulk density ranged from 1.04 to 1.60 g cm-3. The soil reaction rated as slightly acidic to moderate acidic (5.4 to 6.7). The OM ranged from 0.41 to 3.23% while available P ranged from 0.72 to 9.36 mg kg-1 which was low to medium rate. The exchangeable bases ranged from low to medium rate in the study area. CEC was medium to high rate, which implies the medium nutrient reservoir of the soil. Finally, three soil types, Humic Cambisols, Haplic Luvisol, and Cambic Umbrisols were identified in the study area according to World Reference Base. Using the soils according to their potential and applications of integrated soil fertility managements are essential to keep the sustainability of soil fertility and nutrient availability.

Crop yields and sustainability of soil fertility in an organic paddy-upland rotation system

Crop yields and sustainability of soil fertility in an organic paddy-upland rotation system

Soil Fertility Transitions in the Context of Industrialization, 1750–2000

AbstractFertile soils are essential for human health and nutrition and formed the foundation of human economies for millennia. Soils deserve close attention from environmental and economic historians and sustainability scientists. Most soil history literature addresses failure: misuse of soil, uncontrolled erosion, and the resulting collapse of past civilizations. More important, however, and of urgent interest for our present and future prosperity, are the mundane ways that historical farm communities sustained soil health, even while cultivating the same land for centuries. This article explains five strategies by which European and North American farmers accessed, recycled, replenished, and sustained soil fertility over 250 years. By evaluating inputs, extractions, transfers, and annual balances of potassium, phosphorus, and, especially, nitrogen, it models historical soil management in a variety of agroecosystems in various geographical settings and through time. This biophysical environmental history, based on socioecological metabolism methods borrowed from sustainability science, reveals ongoing adaptation to shifting social and environmental contexts. As industrialization, global trade, and population accelerated, farmers adjusted their soil fertility strategies to keep up with new pressures and opportunities. Each solution to existing soil fertility constraints created new obstacles and bottlenecks. Through the past quarter millennium, farm sustainability meant constant readjustment to new circumstances. As farmers innovated crop choices and rotations, corralled livestock, adopted new technologies, deployed novel energy sources, and expanded into new lands, they increased food productivity to feed growing world population and supply expanding markets, while maintaining the supply of soil nutrients necessary to fertilize next year’s crop.

Spatial variability assessment in Central Farm Soils of Horticultural College and Research Institute, Periyakulam, Tamil Nadu using GIS techniques

A total number of 201 surface soil samples were collected encompassing the fields of Central Farm of Horticultural College and Research Institute, Periyakulam, Tamil Nadu. The GPS data (Latitude ºN and Longitude ºE) were recorded for each sampling site by using GPS-Garmin eTrex Vista HCX model. Field maps were collected and field number wise digitization was done. Soil samples were processed and anlaysed for soil physic-chemical and fertility parameters. Results indicated that soil samples were neutral to alkaline in reaction, non saline, and slightly calcareous to non calcareous in nature. Soil fertility groupings under percent category indicated that the soils were medium in soil organic carbon, low in available nitrogen, medium to high in available phosphorus, medium to high in available potassium, and low in available sulphur. With respect to DTPA extractable micronutrients, Fe, Zn, Mn and Cu were found to dominate by low to medium, low, high, medium to high categories, respectively. HWS-Boron was also recorded under the high category. The nutrient index values of the samples indicated a high status for organic carbon, available P and K, while medium for available N and adequate for available sulphur. With respect to micro nutrients, nutrient index values indicated that adequate for DTPA-Zn and very high for DTPA-Fe, Mn, Cu, and HWS-B. Thematic maps generated on the individual parameters depicted the spatial variability of parameters in the Central Farm of Horticultural College and Research Institute, Periyakulam. In the identified areas of poor fertility status, nutrient deficiency has to be eliminated by the application of organic and /or inorganic sources to maintain sustainable soil fertility status. Soil test-based fertilizer recommendations and micronutrients are to be followed to mitigate nutrient deficiencies and achieve sustained crop production and soil fertility.

Characterization and Classification of Soils of Askate Sub-watershed, South Wollo Zone, Northeastern Ethiopia

Information on soil is an essential in sustainable utilization of soil resources and sound land use planning. Therefore, this study was conducted with the objective of characterization and classification of soil on Askate sub-watershed, northeastern Ethiopia. Four representative soil pedons were opened along topographic position and described on each identified genetic horizons basis on the field for their morphological characteristics following the soil field description guidelines. The morphological properties were examined in the field while physical and chemical properties were analyzed in laboratory. The results of the study were revealed variation in morphological, physical, and chemical properties of the soils. Soil textural classes were sandy loam to loam sandy. The bulk density ranged from 1.04 to 1.60 g cm -3 . The soil reaction rated as slightly acidic to moderate acidic (5.4 to 6.7). The OM ranged from 0.41 to 3.23% while available P ranged from 0.72 to 9.36 mg kg -1 which was low to medium rate. The exchangeable bases ranged from low to medium rate in the study area. CEC was medium to high rate, which implies the medium nutrient reservoir of the soil. Finally, three soil types, Humic Cambisols, Haplic Luvisol, and Cambic Umbrisols were identified in the study area according to World Reference Base. Using the soils according to their potential and applications of optimum organic and inorganic fertilizers are essential to keep the sustainability of soil fertility for better crop production and productivity. Keywords: Pedon, Soil classification, Soil characteristics, Topography. DOI: 10.7176/JBAH/11-3-06 Publication date: February 28 th 2021