Intensive Agricultural Land Use Research Articles

The current state of mountain meadow soils of subalpine pasture ecosystems of the Central Caucasus (elbrus altitudinal zonality)

Intensive recreational, agricultural and logistics land use in uplands leads to their transformation and degradation. Subalpine meadow ecosystems of Central Caucasus are traditionally used for grazing and mowing. The work determined the current state of soils on pastures (mountain meadow-steppe subalpine soil and mountain meadow subalpine soil) and the level of changes of their properties under different stages of pasture degradation were defined. The efficacy of 4-stage assessment system for evaluating the pasture degradation of grasslands dominated by Bromus variegatus M. Bieb. was shown for the assessment of soil cover condition. The reduce of estimated soil indicators and degradation of soils under pastures with maximal degradation stage (DS3) of meadow ecosystems was statistically significant.

Effects of Adapted N-Fertilisation Strategies on Nitrate Leaching and Yield Performance of Arable Crops in North-Western Germany

Groundwater pollution with nitrate is a big challenge for drinking water abstraction in regions with intensive agricultural land-use, specifically with high livestock densities on sandy soils in humid climates. Karst aquifers with high water flow velocities are extremely vulnerable to this problem. To cope with this situation, a field trial with an installation of ceramic suction cups under a randomised block design with a typical north-German cropping sequence of silage maize–winter wheat–winter barley was established in a karst water protection zone. Over three years, reduced nitrogen (N) application rates and N type (mineral or combined organic + mineral fertilisation) were tested for their effects on crop yields and leachate water quality below the root zone. Results showed no significant reductions in crop yields with 10/20% reduced N rates for cereals/maize and only slight reductions in cereal protein content. Nitrate concentration from adapted N rates was significantly lower in treatments with an application of organic fertilisers (−7.74 mg NO3-N l−1) with greatest potential after cultivation of maize; in only mineral fertilised plots the effect was smaller (−3.80 mg NO3-N l−1). Cumulative leaching losses were positively correlated with post-harvest soil mineral nitrogen content but even in unfertilised control plots losses >50 kg N ha−1 were observed in some crop-years. Reduced N rates led to decreased leaching losses of 14% (6.3 kg N ha−1 a−1) with mineral and 29% (20.1 kg N ha−1 a−1) with organic + mineral fertilisation on average overall cops and years. The presented study revealed the general potential of adapted fertilisation strategies with moderately reduced N applications (−10/−20%) to increase leachate water quality without affecting significantly crop yields. However, regionally typical after-effects from yearlong high N surpluses in livestock intensive farming systems are a limiting factor.

Restoring steppe landscapes: patterns, drivers and implications in Russia\u2019s steppes

ContextAgricultural land abandonment across the steppe belt of Eurasia has provided an opportunity for the restoration of steppe landscapes in recent decades. However, global food demands are about to revert this trajectory and put restored steppe landscapes at risk.ObjectivesWe analysed steppe development in southern Russia in the last 40 years, assessed its spatial patterns and drivers of change for several periods.MethodsUsing Landsat imagery, we mapped the permanent steppe and steppe restoration from 1990 to 2018. Based on regression tree models, we evaluate and explain its dynamics. Results were compared with district-level trends in land-use intensities of cropland.ResultsWe found 70% of the steppe in 2018 represented permanent steppe and 30% of former cropland dominantly abandoned in the postsocialism (1990–2000). The permanent steppe and steppe restored in the postsocialism (1990–2000) were located far from settlements, on rough terrain and in districts of the Virgin Land Campaign (1954–1963). In recent decades, the patterns of steppe restoration (2000–2018) were mostly determined by unfavourable agroclimatic conditions and distance from grain storage facilities. The restoration pattern reflects regional differences in land-use intensities, e.g., isolated steppe patches mostly appeared in areas of intensive agricultural land-use.ConclusionsSteppe restoration has appeared in areas marginal for agricultural production, with poor natural conditions and little human footprint. Consequently, the permanent steppe became less fragmented and a more continuous steppe landscape resulted. The remaining isolated steppe patches require attention in restoration programs as they are mostly located in areas of intensive agricultural land-use.

Land use and episodic rainfall as drivers of nitrogen exports in subtropical rivers: Insights from δ15N-NO3−, δ18O-NO3− and 222Rn

Ongoing land-use intensification in subtropical catchments is expected to release more inorganic nitrogen to downstream coastal waters similar to historical changes in temperate ecosystems. Here, we examined spatial and temporal drivers of stream nitrogen loads across a subtropical land-use gradient using the isotopic compositions of nitrate (NO3−-N) and radon (222Rn), a natural groundwater tracer. We investigated eleven subtropical creeks/rivers over contrasting hydrological conditions in Australia. NOx-N (nitrite (NO2−-N) + nitrate (NO3−-N)) accounted for 13.1%, 34.0%, and 42.6% of total dissolved nitrogen (TDN-N) in forest, peri-urban and agricultural creeks, respectively. Following an 80 mm rain event, loads of dissolved inorganic nitrogen (DIN-N) from agriculture catchments reached 368 mg N m−2 catchment area day−1. Forest and peri-urban catchments had aquatic TDN-N loads 17.8% and 31.1% of loads from agricultural catchments. Radon observations suggest that nitrogen and phosphorus loads were driven primarily by surface runoff rather than groundwater discharge. The δ15N-NO3− and δ18O-NO3− values in the agriculture, forest and peri-urban catchments indicate fertilisers and soil nitrogen as the main sources of NO3−-N. However, one of the catchments (Double Crossing Creek) received a mixture of recirculated greywater and chemical nitrogen fertilisers. Isotopic signatures imply significant NO3−-N losses via denitrification during dry conditions. Groundwater discharge played a minor role because regional aquifers were not contaminated by nitrogen. Overall, intensive agricultural land use and episodic rainfall events were the major spatial and temporal drivers of nitrogen loads.

Research on Environmental Risk Control of Highly Intensive Agricultural Land Use Based on Computer Technology and Landscape Scale

Under the background of China’s rigid population growth and the reduction of cultivated land area, the degree of agricultural intensification has been increasing. Pesticides and fertilizers have greatly increased crop yields. However, the large amount of agricultural chemicals input leads to the decline of soil and environmental quality. The environmental pollution caused by agricultural activities is increasing, especially in the high intensive agricultural areas with high land use intensity and a large amount of agricultural chemicals input. Agricultural land use is facing the dual challenges of ensuring food security and ecological environment security, which is an arduous and urgent task to realize the sustainable and healthy development of China’s agricultural countryside. High intensive agriculture gains higher economic benefits, but it also leads to serious environmental consequences. In the face of the increasingly serious problems of agricultural ecological environment, how to guarantee the economic development and control the environmental risk of agricultural land use is an urgent practical problem. Based on this, this paper uses computer technology to analyze the environmental risk control strategy of highly intensive agricultural land use based on the landscape scale.

Long‐Term Shifts in U.S. Nitrogen Sources and Sinks Revealed by the New TREND‐Nitrogen Data Set (1930–2017)

AbstractReactive nitrogen (N) fluxes have increased tenfold over the last century, driven by increases in population, shifting diets, and increased use of commercial N fertilizers. Runoff of excess N from intensively managed landscapes threatens drinking water quality and disrupts aquatic ecosystems. Excess N is also a major source of greenhouse gas emissions from agricultural soils. While N emissions from agricultural landscapes are known to originate from not only current‐year N input but also legacy N accumulation in soils and groundwater, there has been limited access to fine‐scale, long‐term data regarding N inputs and outputs over decades of intensive agricultural land use. In the present work, we synthesize population, agricultural, and atmospheric deposition data to develop a comprehensive, 88‐year (1930–2017) data set of county‐scale components of the N mass balance across the contiguous United States (Trajectories Nutrient Dataset for nitrogen [TREND‐nitrogen]). Using a machine‐learning algorithm, we also develop spatially explicit typologies for components of the N mass balance. Our results indicate a large range of N trajectory behaviors across the United States due to differences in land use and management and particularly due to the very different drivers of N dynamics in densely populated urban areas compared with intensively managed agricultural zones. Our analysis of N trajectories also demonstrates a widespread functional homogenization of agricultural landscapes. This newly developed typology of N trajectories improves our understanding of long‐term N dynamics, and the underlying data set provides a powerful tool for modeling the impacts of legacy N on past, present, and future water quality.

Modeling soil and landscape evolution – the effect of rainfall and land-use change on soil and landscape patterns

Abstract. Humans have substantially altered soil and landscape patterns and properties due to agricultural use, with severe impacts on biodiversity, carbon sequestration and food security. These impacts are difficult to quantify, because we lack data on long-term changes in soils in natural and agricultural settings and available simulation methods are not suitable for reliably predicting future development of soils under projected changes in climate and land management. To help overcome these challenges, we developed the HydroLorica soil–landscape evolution model that simulates soil development by explicitly modeling the spatial water balance as a driver of soil- and landscape-forming processes. We simulated 14 500 years of soil formation under natural conditions for three scenarios of different rainfall inputs. For each scenario we added a 500-year period of intensive agricultural land use, where we introduced tillage erosion and changed vegetation type. Our results show substantial differences between natural soil patterns under different rainfall input. With higher rainfall, soil patterns become more heterogeneous due to increased tree throw and water erosion. Agricultural patterns differ substantially from the natural patterns, with higher variation of soil properties over larger distances and larger correlations with terrain position. In the natural system, rainfall is the dominant factor influencing soil variation, while for agricultural soil patterns landform explains most of the variation simulated. The cultivation of soils thus changed the dominant factors and processes influencing soil formation and thereby also increased predictability of soil patterns. Our study highlights the potential of soil–landscape evolution modeling for simulating past and future developments of soil and landscape patterns. Our results confirm that humans have become the dominant soil-forming factor in agricultural landscapes.

Regional differences determination in the Irkutsk region agricultural land use

For the analysis of regional differences in agricultural land use as the basis of rational and efficient production and procurement of food products of the region it is necessary to study land conditions. To do this, apply the relevant research and identification methods of spatial-temporal trends in the use of agricultural land based on consideration of various economic parameters. Features terms of territorial organization are characterized, as a rule, by their existing natural, socio-economic, historical factors, thereby forming the regional differences of agricultural land use. Analysis of the distribution of municipal areas according to the intensity of agricultural land use describes the state of agriculture in the region, reflecting the peculiarities of the conditions of its territorial organization. The intensity of land use is generally determined by parameters characterizing the quantitative and qualitative characteristics of land use. For these purposes, the following indicators were used as input data: area of agricultural land in municipal districts; acreage of agricultural crops; gross production, technical equipment, and mineral fertilizers. Thus, the paper presents comparative characteristics of land resources of the country and the region. The analysis of agricultural land intensity indicators is carried out among the main agrolandscape areas of the region. Areas with the most intensive and less intensive use of agricultural land are identified.

Hydrochemical characteristics and a health risk assessment of the use of river water and groundwater as drinking sources in a rural area in Jiangjin District, China

To determine the hydrochemical characteristics and health risks associated with their use as drinking water, 54 river water and 44 groundwater samples were collected and analyzed in a rural area of Jiangjin District, Chongqing City. The concentration of solutes in river water and groundwater showed significant spatial variability in the region. A number of dissolved chemical constituents including nitrate (NO3−), nitrite (NO2−), aluminum (Al), arsenic (As), boron (B), barium (Ba), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and selenium (Se) exceeded their respective recommended drinking water limits at some locations. Ternary plots of cations, anions and silica indicated that carbonate weathering was the primary source of major ions in water, followed by silicate weathering. Elevated concentrations of some chemical constituents including NO3− and chloride (Cl−) were found in water samples in areas with the most intensive agricultural land use activities. A health risk assessment indicated that Cl− and NO3− were the most important chemical constituents that were a non-carcinogenic health concern. A carcinogenic health risk assessment indicated that chromium (Cr) and As were the chemical constituents of most concern in water from the area that might be used as a drinking water source. The average annual carcinogenic risks for Cr in drinking water were determined to be in the range of 3.14E−05 and 7.90E−05 for adults and children, respectively. Similarly, the average annual carcinogenic risks for As in drinking water for adults and children were calculated to be in the range of 4.43E−07 and 1.11E−06, respectively. These values are within the risk values of 10−6 to 10−4, which generally indicate that there are health concerns that need to be addressed in more detail. The highest values of carcinogenic risk for drinking water were mainly located in the northern part of the study area where there are industrial activities that are potential sources of arsenic and chromium in surface water and groundwater.

Limiting resources on the reproductive success of a cavity-nesting bee species in a grassland agroecosystem

Intensive agricultural land use can impact pollinators mainly through habitat loss and/or modification. Native bees are negatively affected by agricultural intensification, isolation from natural habitats, decreases in plant diversity, and reduction in the availability of nesting sites. Despite this, in the Pampean region, there are scarce studies about the effect of agricultural activities on native bees. We studied the nesting ecology of the native leafcutter bee Megachile gomphrenoides (Megachilidae) in eight sites immersed in an agricultural matrix, where land use is a mosaic of agricultural land and some semi-natural areas. The sampling was developed using paired trap-nests in fragments without agricultural management and in soybean crops. We aimed to analyse the effects of floral and nesting resources on the abundance, the reproductive success and the parasitism rate of a population of M. gomphrenoides in a Pampean agroecosystem. Floral diversity was significantly correlated with abundance of nests and brood cells, and both parasitism rate and reproductive success of M. gomphrenoides were higher in nests built in fragments without agricultural management when compared to crop areas. Additionally, a negative correlation was found between reproductive success and flower diversity in crop areas. These results suggest that floral diversity is limiting the abundance of M. gomphrenoides nests, its reproductive success as well as its parasitism rate.

Ocena aktywności wybranych osuwisk w rejonie Jeziora Rożnowskiego w świetle badań terenowych oraz analiz różnicowych modeli terenu

Assessment of activities of selected landslides in the Roznowskie Dam Lake region based on field studies and analyses of differential digital models. A b s t r a c t. The article compares results of field assessment of activity of selected landslides in the Roznowskie Lake region, obtained in 2010–2014 with a differential digital models (DDM) from airborne laser scanning data of 2010, 2013 and 2018. Results of DDM analyses were similar to those from field studies. The most difficult task in the field research was to distinguish between active landslides, where the last movements took place over three years after the date of landslide registration, and periodically active landslides, the last visible movements that took place five years ago. The article underlines that not all displacements within the landslides, visible on differential terrain models, are the result of colluvium landslide movement. Sometimes they are due to anthropogenic activities. Differential digital model in the Znamirowice landslide presents terrain changes that have resulted from intensive agricultural land use.

Exploring the Statistical Association Between the Economic, Environmental and Innovative Areas of Performance: The Case of European Union Agriculture

The importance of innovation in agriculture is supported by the effects that innovation has on the growth of the sector's performance in relation to its efforts. The aim of the paper is to identify and to analyse the statistical association between the indicators of agricultural performance, regarding the economic, environmental and innovative aspects at European Union level (EU-28). For this, a study on agriculture from the 28 EU countries was developed using the information available in Eurostat statistics during 2006-2016. To address the research problem, the association analysis and correlation analysis as data analysis methods were used. The data were processed using the functions of IBM SPSS - Version 20. The analysis of the relations between the three areas of agricultural performance, namely economic, environmental and innovative, highlighted the following aspects: i) on average, there was an inverse relationship between economic performance and the environmental one; ii) on average, attracting borrowed capital and increasing indebtedness can enhance the innovative processes in agriculture; iii) the increase in economic performance was positively correlated with the intensive use of agricultural land and high levels of investments in technology. A rich economy has the financial resources to invest in research - development - innovation activities in the agricultural sector, which stimulates the economic performance of farmers and others companies in the related fields. The statistical survey highlighted the direct link between the general level of development of a country's economy and the innovative capacity of the strategic sector represented by agriculture.

Falling through the policy cracks: implementing a roadmap to conserve aerial insectivores in North America

Nebel et al discusses the implementation of a roadmap to conserve aerial insectivores in North America Aerial insectivores are subject to myriad anthropogenic stressors across their annual cycles but there is little evidence that a single factor explains the fluctuations observed among populations and species The expansion of intensive agricultural and urban land use especially over the last 30 years has introduced a range of threats impacting both habitat quantity and quality Direct impacts include habitat loss and degradation, particularly of wetlands, grasslands, and forests, and indirect impacts of stressors that reduce the quality of breeding, foraging, and roosting sites The response by Canadians to the COVID-19 pandemic amply demonstrates that rapid changes are possible when we work together to surmount challenges

Микробиологическая оценка состояния почвенного покрова агролесомелиоративных ландшафтов Каменной Степи

The microbial biomass content is the most informative indicator for early detection of soil condition. Soil microorganisms support the homeostasis of forest ecosystems due to theunique ability of rapid adaptation to changing environmental conditions. The article presents the results of soil microbiological assessment carried out within the framework of comprehensive monitoring studies of the forest ecosystems of the Kamennaya Steppe. The following objects of the agroforestry permanent study area served as options: a mowing fallow of 1882; forest belt no. 40 of 1903 laying out, located on the watershed area; forest belt no. 133 of 1950 planting; and forest belt no. 131 of 1959 planting. Additionally, arable lands adjacent to forest belts no. 40 and 133 (watershed, slope) were included in the research scheme. The research purpose was to determine the biological activity of soils of the Kamennaya Steppe, as wellas the direction and intensity of soil and biological processes in agroforestry arrangement of the territory. The total number and structure of ecological and trophic groups of the microbial community were determined by the method of E.Z. Tepper by seeding on solid nutrient media. It is shown that the soil cover under the tree plantation is defined by a higher contentof ammonifiers and actinomycetes. Intensive agricultural land use significantly reduces the intensity of microbiological processes. The undertaken studies allow stating that the optimumconditions for the development of micromycetes are formed in soils under woody and native steppe vegetation. The involvement of chernozems in active agricultural production leads toa decrease in the number of fungal flora. A high concentration of nitrifiers was revealed in arable lands. The lands with woody vegetation and steppe cenoses had lower indices and weresomewhat inferior to agrogenic soils. Annual soil cultivation is crucial and drives up the activity of bacterial colonies (genus Azotobacter) on arable lands. The activity is much lowerunder the tree crops and steppe vegetation in most cases. Mineralization coefficients are calculated for the studied soils. Due to the fact that these coefficients in all the studied objects are above one (except the field under winter wheat and bordering the forest belt no. 133), it follows that the mineralization processes of soil organic matter prevail over the decomposition of organic residues.For citation: Sautkina M.Yu., Cheverdin Yu.I. Microbiological Analysis of the Soil Cover of the Kamennaya Steppe Agroforestry Landscapes. Lesnoy Zhurnal [Russian Forestry Journal],2019, no. 6, pp. 62–78. DOI: 10.17238/issn0536-1036.2019.6.62Funding: The research was carried out within the framework of the state assignment of the All-Russian Research Institute of Forest Genetics, Breeding and Biotechnology.

Quantifying cryptic function loss during community disassembly

Abstract Emerging theory suggests that the ecosystem‐level consequences of anthropogenic pressures depend on how species will be disassembled from ecological communities (i.e. the disassembly rule). Species loss, however, is not the sole ecological cause of ecosystem function loss: behaviours underpinning ecosystem function can also be disrupted by anthropogenic pressures without detectable declines of component species (‘cryptic function loss’). Here, we introduce a novel framework that integrates behavioural responses into community disassembly metrics. We applied this framework to freshwater mussel communities (order Unionida) of the midwestern United States, in which intensive agricultural land use threatens stream biota. We combined a field experiment, meta‐analysis and watershed‐scale population dataset to assess how excessive sediment concentrations, one of the leading drivers of freshwater biodiversity loss, influence community‐level water clearance rates of freshwater mussels via behavioural (changes in mass‐specific clearance rate) and population (changes in population density) responses. Our study provided three key insights. First, freshwater mussels exhibited high behavioural sensitivity to increased total suspended solids (TSS) across species (i.e. reduced water clearance rate), whereas population responses were highly species‐specific. Second, the behavioural response to increased TSS causes substantial cryptic function loss under stressful conditions: simulated water clearance rates when behavioural response is included can be less than half that of mussel communities with no behavioural response. Finally, simulations revealed that mussel communities are likely to show rapid but consistent rates of ecosystem function loss irrespective of disassembly rules. The similar rates of function loss are due to the uniform behavioural response to TSS that masks the linkage between population sensitivity of a species and its contribution to ecosystem function. Synthesis and applications. Our findings suggest that ignoring behavioural processes may cause non‐negligible underestimation of ecosystem function loss during community disassembly, potentially leading to overly optimistic assessments of ecosystem resilience. Furthermore, unlike species declines or local extinctions, behaviour response tied to function loss may occur concurrently with increasing anthropogenic pressures. Therefore, managers should acknowledge the risk of immediate function loss after human‐induced environmental changes.

Soil acidification of the soil profile across Chengdu Plain of China from the 1980s to 2010s

Soil acidification is a major environmental issue associated with intensive agricultural land use. Rapid urbanization has inevitably caused great changes in agricultural land use around urban areas. However, the effects of agricultural land-use change and soil parent material on the pH dynamics of the whole soil profile remain poorly understood. Based on a paired soil resampling campaign in the 1980s and 2010s, this study evaluated the effects of agricultural land-use change and parent materials on the pH dynamics of the soil profile across the Chengdu Plain of China. The results showed that soil pH significantly decreased by 1.20, 0.72, 0.66 and 0.68 units at the 0–20, 20–40, 40–60 and 60–100 cm soil depths, respectively. Conversions of traditional rice-wheat/rapeseed rotations to rice-vegetable rotations and afforested land significantly increased the magnitude of pH decline at the 0–60 cm soil depth. Soils formed from Q4 grey-brown alluvium and Q4 grey alluvium, which had a lower soil bulk density (BD) and higher sand content, showed a much higher magnitude of pH decline than soils formed from Q3 (Quaternary Pleistocene) old alluvium, and significant acidification of deep soils only occurred in soils formed from Q4 (Quaternary Holocene) grey-brown alluvium and Q4 grey alluvium. These results suggested that agricultural land-use change aggravated acidification in the soil profile and the soil acidification degrees were parent material-dependent; in particular, significant acidification of deep soils was more inclined to occur in soils with lower soil BD and higher sand content due to their effects on the downward movement of acids and the penetration resistance of plant roots. More attention should be given to minimizing or preventing acidification of both topsoil and deep soils aggravated by agricultural land-use change across urban agricultural areas.

Magnetometry of the Scythian burial ground Katerinovka in the Lower Dnieper region

The magnetometry of the Katerinovka burial ground (Nikopol district, Dnipropet-rovsk region, Ukraine) conducted on the area of 3.65 hectares showed three times more kurgans than they were visually detected or deciphered from satellite images. Archaeological excavations performed throughout the whole territory of geomagnetic survey area showed that most of the kurgans (24) belong to the Scythian epoch (IV century BC). There were also four burial mounds of the Golden Horde time (XIII—XIV centuries) and one — of the Bronze Age (beginning of the III millennium BC). Anomalies of magnetic induction (Bа) on the burial ground were mainly caused by objects deepened into the loess parent rock with magnetic susceptibility k = (0,3 ¸ 0,4) × 10–3 SI units and puddled with dark humus soil with k = (0.7 ¸ 0.9) × 10–3 SI units. The structural elements of the kurgans — pits, catacombs, ditches, and near-kurgan grooves — create weak (2—10 nT) anomalies of geomagnetic induction, which are reliably recorded using cesium magnetometers even under conditions of intense manmade interference from a heavy machinery in a quarry nearby. The fact of the existence of the near-kurgan grooves, from where the soil was taken to pour the Scythian mounds, was discovered for the first time from magnetometry results. The Bronze Age kurgan was identified by the semiring Bа anomaly from the groove 15—20 m wide. Among 10 burials, only two, the deepest ones, have created Bа anomalies with an intensity of 1.5—5.4 nT. Golden Horde kurgans were defined on the Bа map by weak ring anomalies from the ditches, as well as from the burnt bricks heaps covering some burials. The results of geomagnetic survey and archaeological excavations on the anomalies proved the inter-kurgan space of the visible mounds to be full of smaller sized and worse preserved kurgans. It has been shown that there is an urgent need to use high-resolution magnetometry at registering and studying the kurgan monuments of Ukraine, especially in areas of intensive industrial and agricultural land use.

Perceived Effects of Climate Variability on Cassava Production among Small Scale Farmers in Anambra State, Nigeria

Climate variability is one of the predominant themes in agricultural research. Climate variations can seriously affect agricultural production. It brings about changes in weather patterns which in turn give rise to imbalances in seasonal cycles, harm to ecosystems and water supply affecting agriculture and food production. Extreme weather events such as floods, landslides and drought are caused by climate variation. Studies have shown that root crops such as cassava are most vulnerable to the impact of climate variability. This paper therefore investigated the perceived effects of climate variability on cassava production among small scale farmers in Anambra State. Specifically, the study described the socioeconomic characteristics of small scale cassava farmers in the state; identified the activities of small scale cassava farmers that contribute to climate variability; and ascertained the perception and levels of awareness of climate variability by small scale cassava farmers in the study area. A multi-stage sampling technique was used in selecting the sample units for the study. The instrument for data collection was a well-structured questionnaire based on the objectives. Descriptive statistics was used to actualize the objectives while the hypothesis was tested using multiple linear regression model. The result of the socioeconomic variables showed that majority of the small-scale cassava farmers were within the age range of 41-50 years; majority (59.38 %) of the respondents were females; majority (32.03%) have 7 to 11 years of farming experience; majority of the respondents (35.94 %) have farm size of 0.1 to 0.5 hectares; majority of the farmers (42.19 %) belong to 3 to 4 farming organizations; majority of the farmers (42.19 %) make income of ₦50,000 to ₦100,000; and majority of the farmers (53.13 %) produce yield of 3000 to 4000 kg of cassava. Result of the activities of small scale cassava farmers that contribute to climate variability show that majority of the farmers (88.28 %) perceived that bush burning contribute to climate variability while (82.03%), (60.16%), (56.25%) and (50.78%) indicated that intensive agricultural land use, use of inorganic fertilizers, use of fossil fuels and deforestation contribute also to climate variability, respectively. Based on the perception and level of awareness of climate variability by small scale cassava farmers in the study area, the result show that the farmers were significantly aware of the following climate variability; early onset of rainfall and early cessation; decreased rainfall days; shorter than normal rainfall; absence of frost; low intensity rainfall; flash flooding; unusual patterns of precipitation and high sunshine intensity. It was also found that significant relationship exists between socio-economic characteristics and production level by the small scale cassava farmers. Recommendations were made based on the findings.

Solute Fluxes Through Restored Prairie and Intensively Managed Critical Zones in Nebraska and Iowa

Agricultural activities in the Midwestern United States have potentially altered geochemical fluxes within the critical zone (CZ) compared to native prairie systems that previously dominated the region. To quantify the impact of agricultural land use on soil and stream solute behavior, we studied two watersheds in the region: Glacier Creek Preserve (GCP) in eastern Nebraska and the Intensively Managed Landscapes Critical Zone Observatory (IML-CZO) in eastern Iowa. Both watersheds were initially under agricultural land use for over 100 years, but part of each watershed was restored to prairie 20 – 50 years ago. Soils at both sites formed in thick loess (≥6 m) overlying glacial till with similar mean annual temperatures (~10 °C) but slightly higher mean annual precipitation in Iowa (89 cm) compared to Nebraska (78 cm). At both sites, soil pore water and precipitation were collected every two to four weeks to measure anions, cations, and alkalinity; stream waters draining either restored prairie or agriculture were sampled similarly in Nebraska. Both soil moisture content and electrical conductivity were consistently higher in the upper one meter of agricultural soils compared to prairie soils in Nebraska, implying slower drainage and higher solute concentrations in the agricultural soils. At both sites, soil pore water Ca+2 and Mg+2 concentrations and annual fluxes were significantly higher in agricultural soils compared to restored prairie. Conversely, streams draining restored prairie have significantly higher Ca+2 and Mg+2 concentrations than the agricultural streams. Fluxes from agricultural streams, however, were higher than the prairie, pointing to a potential dilution effect of runoff from the agricultural land use. These observations lead to a conceptual model where deeply infiltrating water in restored prairie soils interacts with minerals present deeper in the soil before reaching the stream whereas in agricultural soils water does not infiltrate as deeply and thus experiences more shallow flowpaths to the stream. Furthermore, changes in geochemical and hydrologic fluxes have been realized in just a few decades since switching land use from agriculture to prairie. Thus, intense agricultural land use may alter soil function and solute transport to streams compared to critical zones hosting tallgrass prairie vegetation.

Organic fertilizer applicators design for supporting rice production

Intensive agricultural land use tends to reduce the content of organic matter in the soil. Organic content in the soil affects the soils ability to bind water and the efficiency of fertilizer absorption by plants as well as an important source of nutrients for plants. Therefore, the addition of organic matter in the form of compost is essential for maintaining the productivity of agricultural land. Problems that occur at the time of application of compost is needed workforce and considerable expense, so it needs an efficient technology in the form of mechanical equipment that is simple and easy to operate. The purpose of this research is to design an organic fertilizer applicator for paddy that can be operated on rice fields. Applicators have been made and functioning well and able to apply organic fertilizer with a dose of 15 tons/ha.