The Complex Effect of Different Tillage Systems on the Faba Bean Agroecosystem.

The interactions of the different factors in differently tilled faba bean agroecosystems are still insufficiently studied and evaluated. For these reasons, we studied the results of a long-term field experiment, which was carried out in the Research Station of Vytautas Magnus University, Agriculture Academy (Lithuania). The aim of this study is to comprehensively evaluate the effect of the deep ploughing (DP), shallow ploughing (SP), deep cultivation, chiseling (DC), shallow cultivation-disking (SC), and no-tillage (NT) systems for the faba bean agroecosystem on the complex interactions of the indices, the relations among the indices, and the strength of the impact; the study employs the integrated evaluation method, which uses the complex evaluation index (CEI). CEI values showed that the NT system had a greater effect on the increase of soil aggregate stability (61%), the decrease of CO2 emissions (12%), and the increase of seed yield (6%) than the DP system. However, the NT system had 36% and 20% higher effect on weed density and biomass increase than DP. CEI values of the DP system were often minimal, i.e., close to 1, which showed the DP system's ineffectiveness.

Analyzing the Influence of Conservation Tillage and Manure on Soil Parameter Modulations in Croplands.

Nowadays, when the human impact on the environment becomes prominent daily, specific steps are needed to mitigate or halt those changes. By far, agricultural land is most affected by the degradation process, leading to soil erosion and decreased soil quality. Sustainable measures are needed to find a solution to that problem. This study, located in an agricultural area in northwestern Croatia, gives an insight into how different tillage systems (conventional and conservation) with the addition of manure will affect soil physicochemical properties, hydrology response, and overall yield. To assess hydrological response, a rainfall simulator was used; meanwhile, soil samples were taken to determine bulk density, soil water content, water-stable aggregates, and soil organic matter. Soil water content did not show significant differences, whereas bulk density and penetration resistance yielded significantly higher values at 15-30 cm depth compared to 0-15 cm depth. Also, the conservation manure recorded lower bulk density and penetration resistance values than conventional tilled treatments. Water-stable aggregates and soil organic matter were severely affected by manure addition and yielded an increase after harvest. Hydrological response was delayed for the treatments with manure addition. Crop yield was also significantly higher for the conventional treatment with manure addition, whereas the control plots had lower yields. The results of this study show the positive aspects of conservation tillage, especially with manure addition, where soil quality is preserved or even increased.

Do tillage systems affect the cadmium threshold in farmland soil for environmental quality standard setting?

Tillage systems may change the cadmium (Cd) threshold of farmland soil. However, there have been few studies on this topic. Therefore, this study aimed to explore the influence of tillage systems on Cd threshold. The study conducted 2-year field experiments under different tillage systems (early rice-fallow, early rice-late rice and early rice-vegetable) at three typical Cd-polluted sites in China. The species sensitivity distribution (SSD) method was used to construct the SSD curves for the calculation of the Cd threshold by analyzing the experimental data. The sensitivity analysis results based on the SSD curves revealed that the sensitivities to Cd in rice varieties under the same tillage system were substantially different but almost the same under different tillage systems. These results can help select rice varieties with low Cd sensitivity for crop safety. Different tillage systems at the same site varied in their influence on Cd threshold values. Cd threshold values under early rice-late rice (e.g., 0.27, 0.28 mg/kg in Xiangtan City) and early rice-vegetable (e.g., 0.26, 0.31 mg/kg in Xiangtan City) tillage systems were roughly lower than that under the early rice-fallow tillage system (e.g., 0.33, 0.35 mg/kg in Xiangtan City). Notably, the influence of tillage systems resulted in Cd threshold values being generally lower than the Cd risk screening values of the current Chinese soil environmental quality standard. Analysis of the influence of different tillage systems on the Cd threshold is beneficial for the optimization of farmland soil environmental quality standards.

Impact of the Cultivation System and Plant Cultivar on Arbuscular Mycorrhizal Fungi of Spelt (Triticum aestivum ssp. Spelta L.) in a Short-Term Monoculture.

Native communities of arbuscular mycorrhizal fungi (AMF) constitute a natural biofertilization, biocontrol, and bioprotection factor for most agricultural crops, including cereals. The present study investigated the native AMF population in cultivated spelt, i.e., a cereal that has not been analyzed in this respect to date. In particular, the aim of the study was to determine the number of spores and the degree of AMF root colonization in two spelt cultivars (Franckenkorn and Badengold) from a 3-year monoculture grown in two different cultivation systems: conventional tillage and no-tillage systems. The study showed considerable accumulation of AMF spores in the soil (on average 1325 in 100 g of air-dry soil), with a wide range of their numbers, and not a very high degree of endomycorrhizal colonization (on average from 3.0% to 31%). The intensity of AMF growth in the subsequent cultivation years gradually increased and depended on the cultivation system as well as the growth stage and cultivar of the spelt. It was found that both analyzed AMF growth indices in the no-tillage system were positively correlated with each other. Moreover, their values were higher in the no-tillage system than in the conventional system, with statistical significance only for the number of spores. This was mainly observed in the variant with the Franckenkorn cultivar. The effect of the growing season was evident in both cultivation systems and spelt cultivars. It was reflected by intensification of sporulation and mycorrhization of spelt roots by AMF in summer (maturation stage) compared with the spring period (flowering stage).

Soil carbon sequestration, greenhouse gas emissions, and water pollution under different tillage practices.

Tillage is a common agricultural practice and a critical component of agricultural systems that is frequently employed worldwide in croplands to reduce climatic and soil restrictions while also sustaining various ecosystem services. Tillage can affect a variety of soil-mediated processes, e.g., soil carbon sequestration (SCS) or depletion, greenhouse gas (GHG) (CO2, CH4, and N2O) emission, and water pollution. Several tillage practices are in vogue globally, and they exhibit varied impacts on these processes. Hence, there is a dire need to synthesize, collate and comprehensively present these interlinked phenomena to facilitate future researches. This study deals with the co-benefits and trade-offs produced by several tillage practices on SCS and related soil properties, GHG emissions, and water quality. We hypothesized that improved tillage practices could enable agriculture to contribute to SCS and mitigate GHG emissions and leaching of nutrients and pesticides. Based on our current understanding, we conclude that sustainable soil moisture level and soil temperature management is crucial under different tillage practices to offset leaching loss of soil stored nutrients/pesticides, GHG emissions and ensuring SCS. For instance, higher carbon dioxide (CO2) and nitrous oxide (N2O) emissions from conventional tillage (CT) and no-tillage (NT) could be attributed to the fluctuations in soil moisture and temperature regimes. In addition, NT may enhance nitrate (NO3-) leaching over CT because of improved soil structure, infiltration capacity, and greater water flux, however, suggesting that the eutrophication potential of NT is high. Our study indicates that the evaluation of the eutrophication potential of different tillage practices is still overlooked. Our study suggests that improving tillage practices in terms of mitigation of N2O emission and preventing NO3- pollution may be sustainable if nitrification inhibitors are applied.

Optimizing interaction between crop residues and inorganic N under zero tillage systems in sub-humid region of Kenya.

Conservation agriculture practices involving zero tillage and residue retention are promising nutrient management strategies for soil health restoration. Despite their potential positive impact on soil fertility, improved crop yields and increased revenues for smallholder farmers; their effect on nitrogen inputs and crop growth is not clearly understood. This may limit their potential as a nutrient management strategy that may remedy soil degradation and boost crop yields for farmers. This study investigated how different tillage practices, crop residues and inorganic nitrogen (N) options affect maize production, soil fertility and economics of smallholder farming systems. The study was conducted in a short-term (2 years) on-station trial, under randomized complete block design with three replications in a maize monocrop system. Six treatments, involving three different rates of maize stover residue (0, 3 and 5 t ha-1) and inorganic N (0, 3 and 5 t ha-1) inputs, respectively, were assessed under conventional and zero tillage systems. Mineral N and organic C were assessed at four depths (0-10 cm, 10-30 cm, 30-60 cm and 60-90 cm) whereas soil aggregate distribution was assessed at 0-5 cm, 5-10 cm, 10-15 cm and 15-20 cm depths. Application of inorganic N as the only input increased (p ≤ 0.05) grain yield (with the yields doubling in the short rains (SR) of 2015 and increasing by 1.4 times in long rains (LR) of 2016) compared to unfertilized control treatment. Treatment, soil depth and the time of sampling significantly affected soil mineral N concentration (p ≤ 0.05). Soil organic C reduced significantly (p ≤ 0.05) with sampling depths, but no differences were observed across treatments. At 0-5 cm depth, the proportion of large macroaggregates in zero tillage increased (48%; p ≤ 0.05) after application of crop residues at 5 t ha-1 relative to 3 t ha-1. Zero tillage treatment with application of 5 t ha-1 of residue and 80 kg N ha-1 was the most dominant and most profitable compared to the other treatments. This treatment had a benefit cost ratio (BCR) of 2.9 (in the short rains season of 2015) and 3.0 (long rains of 2016 seasons). Its marginal rate of return (MRR) was 368% (in the 2015 short rains season) and 416% (in the 2016 long rains season). This makes it a good nutrient management strategy with potential of optimizing maize yields.

Effect of tillage systems and tillage direction on soil hydrological properties and soil suspended particle concentration in arable land in Uganda.

The 2030 Agenda for Sustainable Development addressing the issues of environmental degradation has been challenged by human developments and activities. Crop production systems and technologies (e.g. soil tillage) are among the leading factors causing environmental degradation. In this study, the effect of soil tillage systems (i.e. no-tillage (NT); stubble-mulching (SM); deep tillage (DT); and conventional tillage (CT)) on surface runoff volume (SRV), suspended sediment concentration (SSC), infiltration rate (IR), and soil moisture content (SMC) in the common bean (Phaseolus vulgaris L.) farms, Mukono District, Uganda was evaluated. The effect of soil tillage direction on SRV was also assessed. The SRV, SSC, IR, and SMC were monitored under Complete Randomized Block Design (CRBD) experiments with four soil tillage systems in Goma and Kimenyedde experimental sites during two wet seasons. The results showed that SRV, SSC, IR, and SMC were significantly (p < 0.05) influenced by the soil tillage system, season, and site. The highest total SRV was observed during the first season in Goma experimental site under CT with soil tillage along the slope (1071.3 mm). The lowest SRV was observed during the second season in Kimenyedde experimental site under NT (165.0 mm). The highest and lowest mean SSC was observed in the CT (2.41 ± 0.3 g L-1) in Goma experimental site during the first season and NT (0.43 ± 0.1 g L-1) in Kimenyedde experimental site during the second season, respectively. The SSL was highest under CT in both Goma (147.17 kg ha-1season-1) and Kimenyedde (114.93 kg ha-1season-1), and lowest under NT with the means of 11.25 and 9.19 kg ha-1season-1 in Goma and Kimenyedde experimental sites, respectively. Both SRV and SSC increased linearly with both rainfall amount (RF) and rainfall intensity at 10 min (RI10). The highest and lowest IR and SMC were observed in the NT and CT treatments, respectively. No significant (p > 0.05) variations were observed in the SMC under the NT and SM treatments. Overall, soil tillage systems, soil type, and rainfall characteristics are among the key factors influencing the magnitudes of SRV and SSC in both time and space. This particular study suggests that NT and SM would help reduce the magnitudes of SRV and SSC, in agricultural fields.

Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta-analysis.

The adoption of less intensive soil cultivation practices is expected to increase earthworm populations and their contributions to ecosystem functioning. However, conflicting results have been reported on the effects of tillage intensity on earthworm populations, attributed in narrative reviews to site-dependent differences in soil properties, climatic conditions and agronomic operations (e.g. fertilization, residue management and chemical crop protection). We present a quantitative review based on a global meta-analysis, using paired observations from 165 publications performed over 65 years (1950-2016) across 40 countries on five continents, to elucidate this long-standing unresolved issue. Results showed that disturbing the soil less (e.g. no-tillage and conservation agriculture [CA]) significantly increased earthworm abundance (mean increase of 137% and 127%, respectively) and biomass (196% and 101%, respectively) compared to when the soil is inverted by conventional ploughing. Earthworm population responses were more pronounced when the soil had been under reduced tillage (RT) for a long time (>10 years), in warm temperate zones with fine-textured soils, and in soils with higher clay contents (>35%) and low pH (<5.5). Furthermore, retaining organic harvest residues amplified this positive response to RT, whereas the use of the herbicide glyphosate did not significantly affect earthworm population responses to RT. Additional meta-analyses confirmed that epigeic and, more importantly, the bigger-sized anecic earthworms were the most sensitive ecological groups to conventional tillage. In particular, the deep burrower Lumbricus terrestris exhibited the strongest positive response to RT, increasing in abundance by 124% more than the overall mean of all 13 species analysed individually. The restoration of these two important ecological groups of earthworms and their burrowing, feeding and casting activities under various forms of RT will ensure the provision of ecosystem functions such as soil structure maintenance and nutrient cycling by "nature's plough."

Experimental analysis of CO2 emissions from agricultural soils subjected to five different tillage systems in Lithuania.

Intensive agricultural production strongly influences the global processes that determine climate change. Thus, tillage can play a very important role in climate change. The intensity of soil carbon dioxide (CO2) emissions, which contribute to the greenhouse effect, can vary depending on the following factors: the tillage system used, meteorological conditions (which vary in different regions of the world), soil properties, plant residue characteristics and other factors. The main purpose of this research was to analyse and assess the effects of autumn tillage systems with different intensities on CO2 emissions from soils during different seasons and under the climatic conditions of Central Lithuania. The research was conducted at the Experimental Station of Aleksandras Stulginskis University from 2009 to 2012; and in 2014. The soils at the experimental site were classified as Eutric Endogleyic Planosol (Drainic). The investigations were conducted using five tillage systems with different intensities, typical of the Baltic Region. Deep conventional ploughing was performed at a depth of 230-250 mm, shallow ploughing was conducted at a depth of 120-150 mm, deep loosening was conducted at depths of 250-270 mm, and shallow loosening was conducted at depths of 120-150 mm. The fifth system was a no-tillage system. Overall, autumn tillage resulted in greater CO2 emissions from the soil over both short- and long-term periods under the climatic conditions of Central Lithuania, regardless of the tillage system applied. The highest soil CO2 emissions were observed for the conventional deep ploughing tillage system, and the lowest emissions were observed for the no-tillage system. The meteorological conditions greatly influenced the CO2 emissions from the soil during the spring. Soil CO2 emissions were enhanced as precipitation and the air and soil temperatures increased. Long-term investigations regarding the dynamics of CO2 emissions from soils during the maize vegetation period indicated that autumn tillage systems affect the total soil CO2 emissions. The highest (2.17 µmol m(-2)s(-1)) soil CO2 emissions during the vegetation period were observed in the deep ploughing tillage system, and the lowest values were observed (1.59 µmol m(-2)s(-1)) in the no-tillage system.

Effect of tillage systems and permanent groundcover intercropped with orange trees on soil enzyme activities

The objective of this study was to evaluate the effect of different soil tillage systems and groundcover crops intercropped with orange trees on soil enzyme activities. The experiment was performed in an Ultisol soil in northwestern Paraná State. Two soil tillage systems were evaluated [conventional tillage (CT) across the entire area and strip tillage (ST) with a 2-m strip width] in combination with various groundcover vegetation management systems. Soil samples were collected after five years of experimental management at a depth of 0-15 cm under the tree canopy and in the inter-row space in the following treatments: (1) CT-Calopogonium mucunoides; (2) CT-Arachis pintoi; (3) CT-Bahiagrass; (4) CT-Brachiaria humidicola; and (5) ST-B. humidicola. The soil tillage systems and groundcover crops influenced the soil enzyme activities both under the tree canopy and in the inter-row space. The cultivation of B. humidicola provided higher amylase, arylsulfatase, acid phosphatase and alkaline phosphatase than other groundcover species. Strip tillage increased enzyme activities compared to the conventional tillage system.

Métodos de extração de fósforo e potássio no solo sob sistema plantio direto / Soil phosphorus and potassium extractant in soils under no tillage

A análise de fósforo e potássio no solo, nos Estados do Rio Grande do Sul e de Santa Catarina, é realizada com a solução de Mehlich-1, e os estudos de seleção de métodos de análise para esses elementos foram feitos apenas para o sistema de cultivo convencional. Neste trabalho, a solução de Mehlich-1 foi comparada com a solução de Mehlich-3 e com o método da resina de troca iônica para análise de fósforo e potássio, em solos sob plantio direto, com experimentos de resposta das culturas à adubação fosfatada e potássica instalados no Rio Grande do Sul. As quantidades de fósforo extraídas pelos métodos da resina e Mehlich-3 foram maiores com a solução de Mehlich-1, independentemente da profundidade de amostragem. As quantidades de fósforo extraídas pelos métodos apresentaram alto grau de associação entre si. Para o potássio as quantidades extraídas foram semelhantes entre as metodologias estudadas, com alto grau de associação entre si, independentemente da profundidade de amostragem. As metodologias estudadas são eficientes na extração de fósforo e potássio no solo, em sistema plantio direto. Porém, devido às menores quantidades de P extraído pela solução de Mehlich-1, os erros em laboratório podem ser maiores pela menor amplitude de extração.

The current soil test method used to evaluate soil phosphorus and potassium available to the plants in soils from Rio Grande do Sul e Santa Catarina state is the Mehlich-1 solution. The soil test methods studies for these nutrients were conducted based on the conventional soil tillage. The aim of this work was to compare the soil phosphorus and potassium amounts extracted by the Mehlich-1 solution and the nutrients amounts extracted by the Mehlich-3 solution, and resin membrane in soils from the Rio Grande do Sul state, under no tillage soil system and nutrients crop response. The phosphorus amounts extracted by the resin method and by the Mehlich-3 solution were higher than that those extracted by the Mehlich-1 solution in both of them sampling depth. The correlation coefficients among the phosphorus amounts extracted by the methods were high association degree. The potassium amounts extracted by the methods were similar, and the correlation coefficients among the potassium amounts extracted by the methods were high association degree in all soil sampling depth. The soil testing methods that have studied in this work are efficient for soil phosphorus and potassium extraction in soils under no tillage; however, the lowest soil phosphorus amounts extracted by the Mehlich-1 solution, increase the laboratory errors.

Consumo de água e produção de grãos do feijoeiro irrigado em sistemas plantio direto e convencional / Water consumption and grains production by irrigated beans in no tillage and conventional systems

O uso inadequado dos recursos hídricos na agricultura, em busca de elevadas produtividades, tem causado impactos negativos nas reservas de água, diminuindo a eficiência dos sistemas produtivos irrigados. O objetivo deste trabalho foi determinar o consumo de água por meio dos coeficientes de cultura para o feijoeiro irrigado por aspersão, nos diversos estádios de seu desenvolvimento, mais a produção de grãos e seus componentes, em sistema plantio direto e convencional. O manejo da irrigação foi realizado por tensiômetros, para manter o conteúdo de água no solo entre 28 (momento de irrigar) e 31 por cento (capacidade de campo). A evapotranspiração da cultura (ETc) foi determinada pelo balanço hídrico a campo, e a evapotranspiração de referência foi (ETo) calculada pelo método de Penman-Monteith, sendo utilizados os dados climáticos obtidos junto à Estação Meteorológica instalada na área experimental. Os resultados indicam que os coeficientes de cultura do feijoeiro nos estádios de florescimento e enchimento de grãos, em sistema plantio direto, apresentam os menores valores quando comparado ao sistema convencional. As plantas do feijoeiro no sistema plantio direto são mais eficientes no uso da água, pelo fato de apresentarem, nesse sistema, maior produtividade de grãos com menor consumo de água.

The inappropriate use of water resources in agriculture, to get higher yields, has caused negative impacts on soil water storage, reducing the efficiency of irrigated productive systems. The aim of this research was to study water use through crop coefficients for sprinkler-irrigated beans at different development stages, in addition to the production of grains and their components, in no tillage and tillage crop systems. Irrigation management was monitored with tensiometers to maintain the soil water content level between 28 percent (at the moment of irrigation) and 31 percent (field capacity). The crop evapotranspiration level (ETc) was obtained from the soil water balance and the reference evapotranspiration (ETo) using the Penman-Monteith method. The results indicate that bean crop coefficients show lower values in the no tillage system than in the conventional tillage system, during flowering and pod formation stages. The bean plants in no tillage system are more efficient in relation to water use than the conventional tillage system, because in this system, the bean crop shows higher grain yield with lower water consumption.