Assessing the Impacts of Tillage and Mulch on Soil Erosion and Corn Yield

Fate of endosulfan in ginseng farm and effect of granular biochar treatment on endosulfan accumulation in ginseng

Endosulfan was widely used as an insecticide in the agricultural sector before its environmental persistence was fully understood. Although its fate and transport in the environment have been studied, the effects of historic endosulfan residues in soil and its bioaccumulation in crops are not well understood. This knowledge gap was addressed by investigating the dissipation and bioaccumulation of endosulfan in ginseng as a perennial crop in fresh and aged endosulfan-contaminated fields. In addition, the effect of granular biochar (GBC) treatment on the bioaccumulation factor (BAF) of endosulfan residue in ginseng was assessed. The 50% dissipation time (DT₅₀) of the total endosulfan was over 770 days in both the fresh and aged soils under mulching conditions. This was at least twofold greater than the reported (6- > 200 days) in arable soil. Among the endosulfan congeners, the main contributor to the soil residue was endosulfan sulfate, as observed from 150 days after treatment. The BAF for the 2-year-old ginseng was similar in the fresh (1.682-2.055) and aged (1.372-2.570) soils, whereas the BAF for the 3-year-old ginseng in the aged soil (1.087-1.137) was lower than that in the fresh soil (1.771-2.387). The treatment with 0.3 wt% GBC extended the DT₅₀ of endosulfan in soil; however, this could successfully suppress endosulfan uptake, and reduced the BAFs by 66.5-67.7% in the freshly contaminated soil and 32.3-41.4% in the aged soil. Thus, this adsorbent treatment could be an effective, financially viable, and sustainable option to protect human health by reducing plant uptake of endosulfan from contaminated soils.

Use of Vegetable Residues and Cover Crops in the Cultivation of Maize Grown in Different Tillage Systems

The purpose of research on alternative variants of soil tillage systems related to fertilization, vegetal residues, and cover crops, in the case of the maize crop, is to elaborate and promote certain integrated technologies on conservation agriculture. This paper presents the results of a study conducted in the Transylvanian Plain during 2019–2021, regarding the influence of certain technological and climatic factors on the yield and quality of maize. The objective of the research was to focus on how vegetable residues and cover crops can be integrated into the optimization of the fertilization system of conservation agriculture. A multifactorial experiment was carried out based on the formula A × B × C × D − R: 4 × 2 × 3 × 3 − 2, where A represents the soil tillage system (a1 conventional tillage with moldboard plow; a2 minimum tillage with chisel; a3 minimum tillage with disk; a4 no tillage); B represents the maize hybrid (b1 Turda 332; b2 Turda 344); C represents the vegetable residues and cover crops (c1 vegetable residues 2.5 t ha−1 + 350 kg ha−1 NPK; c2 vegetable residues 2.5 t ha−1 + cover crops mustard; c3 vegetable residues 2.5 t ha−1 + gulle 10 t ha−1); D represents the year (d1 2019; d2 2020; d3 2021); and R represents the replicates. The results emphasized the fact that for the soil conditions from the area taken into account (Chernozem), for maize, a minimum tillage with chisel during autumn + disk harrow in spring + sowing can be considered as an alternative to the conventional tillage system. Yield and quality of maize can be improved and optimized by combined fertilization: vegetable residues and cover crops being supported with different sources of mineral NPK.

Long-term non-sustainable soil erosion rates and soil compaction in drip-irrigated citrus plantation in Eastern Iberian Peninsula

Agriculture is known to commonly cause soil degradation. In the Mediterranean, soil erosion is widespread due to the millennia-old farming, and new drip-irrigated plantations on slopes, such as the citrus ones, accelerate the process of soil degradation. Until now, the published data about soil erosion in citrus orchards is based on short-term measurements. Long-term soil erosion measurements are needed to assess the sustainability of drip-irrigated citrus production and to design new strategies to control high soil erosion rates. The objective of this study is to assess long-term soil erosion rates in citrus plantations and report the changes in soil bulk density as indicators of land degradation. We applied ISUM (Improved Stock-Unearthing Method) to 67 paired trees in an inter-row of 134 m (802 m² plot) with 4080 measurements to determine the changes in soil topography from the plantation (2007) till 2020. Soil core samples (469) were collected (0-6 cm depth) to determine the soil bulk density at the time of plantation (2007) and in 2020. The results demonstrate an increase in soil bulk density from 1.05 g cm^-3 to 1.33 g cm^-3. Changes in soil bulk density were higher in the center of the row as a result of compaction due to passing machinery. Soil erosion was calculated to be 180 Mg ha^-1 y^-1 due to a mean soil lowering of 1.5 cm yearly. The highest soil losses were found in the center of the inter-row and the lowest underneath the trees. The extreme soil erosion rates measured in new drip-irrigated citrus plantations are due to soil lowering in the center of the inter-row and in the lower inter-row position where the incision reached 80 cm in 13 years. The whole field showed a lowering of the soil topography due to extreme soil erosion and no net sedimentation within the plantation. The results show the urgent need for soil erosion control strategies to avoid soil degradation, loss of crop production, and damages to off-site infrastructures.

Water Erosion Reduction Using Different Soil Tillage Approaches for Maize (Zea mays L.) in the Czech Republic

In today’s agriculture, maize is considered to be one of the major feed, food and industrial crops. Cultivation of maize by inappropriate agricultural practices and on unsuitable sites is connected with specific risks of soil degradation, mainly due to water erosion of the soil. The aim of this study was to evaluate the yielding parameters, fodder quality and anti-erosion efficiency of different methods of conservation tillage for maize in two areas (Jevíčko—JEV and Skoupý—SKO) with different climate and soil conditions in the Czech Republic in the period 2016–2018, using multivariate exploratory techniques such as principal component analysis (PCA) and factor analysis (FA). Four variants of soil tillage methods were analysed: Conventional Tillage (CT), two slightly different Strip-Till techniques (ST) and Direct Sowing (DS). The analysed parameters were: dry mass of the plants, height of the plants, starch content (SC), organic matter digestibility (OMD) and content of neutral detergent fibre (NDF), soil loss by erosion and surface runoff. The multivariate exploratory techniques PCA and FA significantly differed in two categories of techniques in both locations. The first category consists of soil conservation techniques (SCT): ST (JEV/SKO) and DS (JEV). These techniques are characterised by lower yields of dry mass, lower height of plants, forage quality equal to CT, but a high level of protection of the soil against erosion. The second category consists of CT (JEV and SKO) and partially of DS (SKO). These treatments are characterised by high dry mass production, higher plants, high forage quality, but a feeble capacity of protection of the soil against erosion. The results of the study confirm the presumption of the positive influence of introduction and application of new agronomical practices in the areas of interest and other areas with similar natural conditions in the sense of sustainable management for agricultural management of agricultural land for the conditions of the Czech Republic and therefore of Central and Eastern Europe. PCA and FA were used as an effective method for comprehensive evaluation of the use of STC in agricultural practice.

Soil Erosion Reduction by Grain for Green Project in Desertification Areas of Northern China

The Grain for Green Project (GGP) encompasses most desertification areas in northern China where fragile soils are susceptible to erosion given the arid and semi-arid climate, low vegetation cover, and strong winds. We collected relevant data through ecological surveys and literature review to quantify total sand fixation and dust retention in 2015 based on different restoration methods, forest types, ecological function zones, and key desertification areas. Our results showed that cropland and wasteland afforestation increased sand fixation and dust retention, whereas facilitate afforestation was less effective in doing so. Further, sand fixation and dust retention values were higher in ecological and shrub forests compared with economic forests, as well as in wind erosion zones compared with wind-water erosion and water erosion zones. Moreover, 43.28% and 44.75% of total sand fixation and dust retention, respectively, were concentrated in important windbreak and sand fixation areas. Similarly, 60% and 30% of total sand fixation and dust retention, respectively, occurred in sandstorm paths and sources. Lastly, policy factors primarily influenced the spatial distribution patterns of both sand fixation and dust retention. Based on these results, enhancement of GGP efficacy into the future will rely on increased restoration efforts specifically aimed at planting more drought-resistant shrubs and native vegetation as doing so will enhance sand fixation, dust retention, and thus, the ecological integrity of these valuable and fragile desert ecosystems in northern China.

Land use change affects water erosion in the Nepal Himalayas

Soil erosion is a global environmental threat, and Land Use Land Cover Changes (LUCC) have significant impacts on it. Nepal, being a mountainous country, has significant soil erosion issues. To examine the effects of LUCC on water erosion, we studied the LUCC in Sarada, Rapti and Thuli Bheri river basins of Nepal during the 1995-2015 period using the Remote Sensing. We calculated the average annual soil loss using the Revised Universal Soil Loss Equation and Geographical Information System. Our results suggest that an increase in the agricultural lands at the expense of bare lands and forests escalated the soil erosion through the years; rates being 5.35, 5.47 and 6.03 t/ha/year in 1995, 2007 and 2015, respectively. Of the different land uses, agricultural land experienced the most erosion, whereas the forests experienced the least erosion. Agricultural lands, particularly those on the steeper slopes, were severely degraded and needed urgent soil and water conservation measures. Our study confirms that the long term LUCC has considerable impacts on soil loss, and these results can be implemented in similar river basins in other parts of the country.