Soil Management Systems Research Articles

Loss of nitrogen, phosphorus, and potassium through surface runoff under simulated rainfall in different soil management systems

Loss of nitrogen, phosphorus, and potassium through surface runoff under simulated rainfall in different soil management systems

Prospecção de rizobactérias promotoras de crescimento de plantas em videiras no Vale do São Francisco

ABSTRACT Viticulture is the main agricultural production in the São Francisco Valley, Brazil; however, farm soil management systems require large volumes of fertilizer that could contribute to climate change. Therefore, using plant growth-promoting rhizobacteria (PGPR) has been reported to reduce or replace plant input. This study aimed to evaluate the bacteria in the rhizosphere of Vitis vinifera cultivated in the São Francisco Valley in Pernambuco, Brazil, and to characterize the mechanisms that promote plant growth. The PGPR with the greatest biotechnological potential was identified using sequencing. The bacteria were isolated from tryptic soy agar (TSA) culture medium inoculated with 100 µL of a serial dilution. The isolates obtained were characterized phenotypically and tested for their ability to solubilize phosphate, promote biological nitrogen fixation (BNF), and produce indole-3 acetic acid (IAA), biofilms, and antibiotic factors against Xanthomonas campestris pv. viticola. A total of 423 bacteria were obtained, of which 99 presented positive results for at least one of the growth-promotion mechanisms, representing 6.85% for phosphate solubilizers, 0.74% for BNF, 5.7% for IAA synthesizers, 11.27% for biofilm producers, and 4.01% for promoting antibiosis against X. campestris pv. viticola. Isolates 3.19 and 31.14; 3.17 and 17.04; 5.35 and 5.42; and 5.37 identified as Stenotrophomonas, Bacillus, Pseudomonas, and Clostridium, respectively, presented a biotechnological potential for future experiments to promote vine growth.

Effects of agricultural management and of climate change on N2O emissions in an area of the Brazilian Cerrado: Measurements and simulations using the STICS soil-crop model

Soil-plant simulation models have been ever more used as predictive tools to evaluate productivity and environmental impacts of agriculture practices. The aims of this work were to evaluate the STICS model’s capacity of simulate the emissions of nitrous oxide (N2O) under different management systems. And, to predict, by applying the calibrated and validated STICS model, the N2O emissions, under different management systems, in the edaphoclimatic conditions of the Brazilian Cerrado. The study was conducted in a long-term experiment at Embrapa Cerrados, located in Planaltina/DF, Brazil. The experiment started in 1995. The following land use systems were evaluated: CT - conventional tillage with disc harrow, and biannual grass/legume rotation; NT1 - No-tillage, with biannual crop rotation – soybean/sorghum; NT2 - No-tillage, with biannual crop rotation – maize/pigeon pea.Closed static chambers and gas sample analysis by gas chromatography were used to measure N2O fluxes. The model was calibrated with the data measured in the CT and NT1 treatments. The attributes used in the calibration were: growth, development and yield of crops and N2O fluxes. To test the model, data from the NT2 treatment was used. Data for all treatments were collected at the same time. After calibration and validation, the STICS model was used to predict the effects of soil management systems, conventional (CT) and no-tillage (NT) on greenhouse gas emissions and on grain and biomass crops production. The simulation was made for the period from 2021 to 2070. The STICS model performed well at simulation of the following parameters: N2O emissions, soil water dynamics, soil temperature; and leaf area, aerial biomass and grain yield of soybean and maize. The performance of the model was good for the conventional soil management system as well as in the no-tillage system. Based on the predicted increase in temperature for the period 2021–2070, we can conclude from the data generated through the STICS model that there is strong evidence that grain yield and total aerial biomass of plants will decrease. The data show that there is a rising tendency in N2O emissions over the simulated period. This is expected to occur for the two soil management systems studied (NT and CT). We believe this increase in emissions along the years is related to temperature increase and to the reduction of crop cycle.

Preparing Maps of the Distribution of Organic Matter and Calcium Carbonate in Northern Iraq

The study area was chosen within the agricultural lands in the north of Kirkuk governorate to prepare a map of organic matter and calcium carbonate content. It identified three sites in Kalwor, Shwan, and Altun Kupri and collected 20 representative surface samples of the soil of agricultural lands in these sites. The maps were prepared in a software environment Arc GIS. 20 surface samples of soil from sites north of Kirkuk were chosen, representative of the nature of land uses, including field crops, rangeland, and barren soils, to study the spatial variations of some chemical soil characteristics of Kirkuk Governorate. The results revealed the nature of spatial variations in the content of organic matter, as it ranged between (0.58-19.54) g kg-1, where the highest value was reached in ton coopers in lands exploited by growing field crops represented by corn, while the calcium carbonate content ranged between (208-365) g kg-1. In conclusion, moderate organic matter content was dominant, specifically in exploited agricultural lands that follow a good soil management system, while the very abundant and plentiful variety was in lands that were not agriculturally exploited. The very high content of calcium carbonate is prevalent in most of the lands of the study area, which need agricultural land management, especially because they suffer from a specific factor, which is the high content of calcium carbonate, and in the future, it may lead to desertification of these lands.

Soil microbial properties are improved by the adoption of soil management and conservation practices in no-tillage system

ABSTRACT No-tillage system (NTS) plays a prominent role in conservation agriculture, however, its benefits can be further improved by adopting complementary soil management and conservation practices, such as using autumnal cover crops, contour seeding, and terraces. This study aimed to evaluate how soil biological activity responds to soil management and conservation systems. The treatments consisted of three macroplots with an area of 11.000 m 2 each, as follows: a) Non-Terraced catchment (NTC), cultivated in NTS similar to most farmers of the region, in which the agricultural operations are carried out in the direction of the slope and without terraces used; b) Best Management Practices (BMPs) were adopted in NTS with additional autumnal cultivation of cover crops, and also the direction of machine traffic was transverse to the slope direction; and c) Terraced catchment (TC), cultivated in NTS was associated to mechanical practices to erosion control, using wide base terrace on level. Soil microbial properties sampled in the 0.00-0.10 m layer were evaluated during 2019, 2020, and 2021, all shortly after the summer crop harvest. Natural inoculum potential of arbuscular mycorrhizal fungi (AMF), respirometry, metabolic coefficient, acid phosphatase activity, and organic carbon and nitrogen in the microbial biomass were assessed. Averages of each microbiological properties were compared through the confidence intervals (p<0.05). The results showed a greater potential for AMF inoculum in BMPs and TC systems. The NTC showed the highest values of respirometry and metabolic quotient, releasing 31.7 and 27.3 % more CO 2 compared to BMPs and TC, respectively. The BMPs and TC were able to retain 13.8 and 16.5 % more carbon in the microbial biomass and 8.0 and 8.8 % more nitrogen in the biomass than NTC, respectively. Adopting soil management and conservation practices such as autumn cover crops, level seeding, and wide base terrace on level improved the soil microbial properties, with an increase in AMF inoculum potential, higher levels of acid phosphatase activity, and increment of carbon and nitrogen in microbial biomass.

Soil Biodiversity: Influence of Soil Management Systems

Aim: Soil represents one of the most diverse habitats found on our planet. Soil organisms play crucial roles within ecosystems by exerting influence over physical properties and processes, as well as contributing to carbon and energy fluxes and the cycling of nutrients. The activity and composition of soil organisms are significantly impacted by land use and land management practices. In this study, we examined the predominant functional groups present in soil two different soil management systems viz., organic and integrated nutrient management (INM).
 Methods: We collected soil samples from coconut-based cropping systems under organic soil management and integrated nutrient management. Soil samples were characterised for soil macrofauna, mesofauna, microfauna and microflora.
 Results: The presence of soil macrofauna, mesofauna, microfauna, and microflora was more pronounced under organic management. Furthermore, the PERMANOVA analysis indicated that while management practices did not significantly impact community dissimilarity in the study area, the depth of the soil did have a significant influence.
 Conclusion: Although the PERMANOVA analysis within the light conditions examined, revealed that the influence of management practices on community dissimilarity was not statistically significant, it was noted that organic management led to an enhancement in soil biodiversity. The results of this study offer a comprehensive evaluation of the manner in which the organic management and INM practices influence the biodiversity of the soil.

No-Tillage System Can Improve Soybean Grain Production More Than Conventional Tillage System.

Soil management systems can directly interfere with crop yield via changes in the soil's physical and hydraulic properties. However, short- to medium-term experiments of conduction do not always demonstrate the modifications of the management systems in these properties. Thus, the aim of this study was to evaluate the physical properties of the soil in a long-term management system and to relate it to the storage and availability of water to plants, verifying its effect on soybean yield. The experiment was conducted in randomized blocks in a split-plot scheme with four replications. Plots were composed by soil management (conventional tillage and no-tillage), and subplots represented three soil depths (0.0-0.1, 0.1-0.2, and 0.2-0.4 m). The soil's physical and hydraulic properties, root development, and soybean yield were evaluated. The no-tillage system not only presented higher bulk density and soil resistance to compaction up to a depth of 0.2 m but also greater root development. This management also did not affect the process of water infiltration in the soil and presented an increase in soybean grain yield by 6.5%. The long-term no-tillage system (33 years) offers less risk of water stress to soybean plants; it contributes to greater grain yield of this crop when compared to the conventional tillage system.

Soil Quality Evaluation for Cotton Fields in Arid Region Based on Graph Convolution Network

Accurate soil quality evaluation is an important prerequisite for improving soil management systems and remediating soil pollution. However, traditional soil quality evaluation methods are cumbersome to calculate, and suffer from low efficiency and low accuracy, which often lead to large deviations in the evaluation results. This study aims to provide a new and accurate soil quality evaluation method based on graph convolution network (GCN). In this study, soil organic matter (SOM), alkaline hydrolysable nitrogen (AN), available potassium (AK), salinity, and heavy metals (iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn)) were determined and evaluated using the soil quality index (SQI). Then, the graph convolution network (GCN) was first introduced in the soil quality evaluation to construct an evaluation model, and its evaluation results were compared with those of the SQI. Finally, the spatial distribution of the evaluation results of the GCN model was displayed. The results showed that soil salinity had the largest coefficient of variation (86%), followed by soil heavy metals (67%) and nutrients (30.3%). The soil salinization and heavy metal pollution were at a low level in this area, and the soil nutrients and soil quality were at a high level. The evaluation accuracy of the GCN model for soil salinity/heavy metals, soil nutrients, and soil quality were 0.91, 0.84, and 0.90, respectively. Therefore, the GCN model has a high accuracy and is feasible to be applied in the soil quality evaluation. This study provides a new, simple, and highly accurate method for soil quality evaluation.

Análise multivariada como ferramenta na seleção de agroecossistemas sustentáveis de cultivo de meloeiro no Semiárido

ABSTRACT Soil management systems, including tillage and green manuring, are important for the control of nematodes and for the sustainable production. The objective was to select, through multivariate analysis, sustainable agroecosystems for yellow melon cultivated under irrigated conditions in the Brazilian semi-arid region. The long-term experiment is set up in Argissolo Vermelho- Amarelo (Ultisol) with six multifunctional agroecosystems, composed of the combination of three mixtures of cover crops (1 - 75% legumes + 25% grasses and oilseeds; 2 - 25% legumes + 75% grasses and oilseeds and 3 - spontaneous vegetation) and two types of soil management (no tillage-NT and tillage-T). The purpose was to evaluate the nutritional status of plants, soil fertility, nematode population in roots and soil, and the yield. Data were analyzed with multivariate techniques, allowing the grouping of the agroecosystems based on their similarities and complexity of functions. The incorporation of plant residues to the soil reduces nematode population, but their maintenance on the surface allows the improvement of fertility and yield, even under larger nematode populations. The agroecosystems that associate the nonincorporation of residues from cover crops with larger species diversity in composition constitute the most complex model, allowing different environmental functionalities. Thus, it is recommended not to incorporate the plant residues, planting the melon seedlings directly in the straw. However, considering that the results obtained with the non-incorporation of spontaneous vegetation were similar to those obtained with the incorporation of commercial cover crops, it is concluded that this practice is also viable and adapted to the semi-arid conditions.

Noticeable Shifts in Soil Physicochemical and Biological Properties after Contrasting Tillage Management in Crop Rotations of Bean, Maize, and Amaranth in Ecuadorian Highland Soils

Soil biological properties are sensitive indicators of soil quality changes due to perturbations occurred under agricultural management. The effects of contrasting tillage, increasing nitrogen fertilization doses, and crop rotations [e.g., bean, maize, bean (BMB) and bean, amaranth, bean (BAB)] on soil physicochemical and biological properties in an Andean soil from Ecuadorian highlands were evaluated in this study. Acid phosphatase, β-Glucosidase, fluorescein diacetate hydrolysis, microbial biomass carbon (Cmic), soil basal respiration (BR), arbuscular mycorrhizal fungi (AMF) spore density, total glomalin content (TGRSP), and soil physicochemical properties were analyzed. Conventional tillage (CT) and crop rotation showed significant effects on soil physicochemical and biological properties. Towards the final crop rotations, no-tillage (NT) promoted BR, TGRSP, and higher AMF spore density in both crop rotations; the Cmic kept stable along time in BMB and BAB, while BR doubled its value when compared to CT. Results indicated that the AMF spore density increased by 308% at the end of the BMB, and 461% at the end of the BAB, while TGRSP increased by 18% and 32% at the end of BMB and BAB, respectively. Biological traits demonstrated to be strongly associated to the organic matter accumulation originated from crop residues under the NT post-harvest which improved soil moisture, biological activity, and AMF interaction. The conservative soil management system has definitively improved general soil properties when compared to soil conditions under the intensive soil management system in this research.

Biogenic and physicogenic aggregates as indicators of quality in soils with sandy texture in areas of organic agriculture

ABSTRACT Sandy texture soils have a great expression in agricultural areas worldwide. In the Baixada Fluminense, soils with a sandy texture on the surface horizons are striking, and a good part of these areas is destined for producing vegetables using conventional cultivation methods. The sandy texture is one of the great challenges for agriculture due to the low water retention capacity provided to the soil, the rapid decomposition of organic matter, and the intense loss of nutrients by leaching. In these areas, the action of erosive processes is sometimes observed, whether water or wind erosion. The practices carried out in conventional agriculture can accentuate these processes. This study aimed to evaluate the influence of different soil management systems, with different vegetation covers, on the pathways of aggregate formation, the nutrient contents contained therein, and the organic matter fractions, with the objective of using these properties as indicators of soil quality. The study was carried out in an organic production unit, with no-till system (NT) and conventional system (CT), three vegetal covers were evaluated, namely; seed cocktail 1 (C1) (Crotalaria (Crotalaria juncea) (20 kg ha -1 ), Jack Bean (Canavalia ensiformis) (150 kg ha -1 ) and millet (Pennisetum glaucum) (60 kg ha -1 )), and seed cocktail 2 (C2) (with 50 % of the amount of seeds used in C1), and spontaneous plants (S. P). Undisturbed samples were collected at the layers of 0.00-0.05 and 0.05-0.10 m, and, from these samples, aggregates with a diameter between 9.7 and 8.0 mm were classified according to the formation route (Biogenic or Physicogenic). From these, the chemical properties were quantified (pH, Ca 2+ , Mg 2+ , Al 3+ , P, Na + , K + ), and also the carbon fractions (total organic carbon – TOC, mineral-associated organic carbon – MAOC), particulate organic carbon – POC, and free light fraction carbon – LFC). Based on the results, it was verified that the percentage of biogenic aggregates was higher than the physicogenic one in the layer of 0.00-0.05 m, not being verified influences of the vegetal coverage or the management system. Chemical properties did not differ significantly between training pathways. The CT, for the most part, was the system in which the highest values of chemical properties were observed, and in general, the C2 and S.P coatings were the ones that provided the greatest improvements for chemical properties and carbon content.

Agricultural practices to improve near-surface soil health and crop yield in subtropical soils

Integrated crop and livestock systems (ICLS) have the potential to minimize soil degradation, improve soil health, and maximize food production. Our goal was to evaluate the impact of no-till (NT) in association with ICLS on soil health and soybean yield in Inceptisol and Oxisol soils in Southern Brazil. The response of physical, chemical, and biological soil health indicators to soil and crop management systems was measured over the short- (<5 years) and long-term (>10 years) under ICLS with soybean in spring/summer and forage grazed by cattle in the autumn/winter. A soil management index was calculated for each soil based on ICLS management. Independent of soil type, ICLS in association with NT for 10+ years improved chemical and biological properties in the near soil surface (0–6 cm depth). The Soil Management Assessment Framework (SMAF) scores for soil organic carbon (SOC), phosphorus (P), and bulk density were close to 1.0 in the Inceptisol, independent of management or soil depth, while the pH scores were lower in the ICLS topsoil. For the Oxisol, the SMAF scores for SOC and P were approximately 1.0 in the 0–6 cm depth under long-term ICLS. The SMAF overall soil quality index was high (approximately 0.9) for both soils and there were no significant differences between management practices. Overall, the adoption of ICLS in association with NT (i) improved or maintained soil health, (ii) promoted soil carbon sequestration, and (iii) increased soybean yield in the studied soils. This study confirmed the potential for conservation practices (ICLS combined with NT) to improve soil quality with environmental sustainability.

Pruning and plucking equipments in horticulture : A review

The various growing techniques and production processes, required to work operations, technical procedures, appropriate techniques for soil management systems, orchard tractors, soil-working equipment, mulching and mowing equipment, post hole diggers, spreaders, sprayers, front-fitted knife trimmers, harvesting equipment, transporting equipment, shakers, harvesters, etc. are all included in modern horticultural mechanization. Harvesting, trimming and spraying still require manual labour and should be automated. In India, the typical farm power density is 1 kW ha-1. Timeliness is limited due to power availability during key operational periods. There is 3.75 kW ha-1 of required power density is thought to be necessary to maintain timeliness of activities. The relevance of regional producers and global markets for machinery and equipment cannot be overstated. New production methods must be the focus of interdisciplinary research including plant scientists, engineers, food scientists, economics, and marketing professionals. The key to innovation is a deep grasp of the system. Certain crops require distinct growing techniques and only then can specialised machinery work. In this review different fruit plucking and pruning equipments were discussed along with the different processes involved for different crops harvesting characteristics.

Evaluation of physicochemical properties with the availability of plant nutrients in forests and crop farms in different Fijian provinces

Soils are the foundation of agriculture and forestry and it provides many functions such as the supply of water and nutrients and anchorage for plant growth and more. Forest farming and agriculture farming are 2 entities of the ecosystem and they may lead to changes in soil properties. To cope with the challenges in the soil management system, data on current chemical and physical soil properties are more necessary. Therefore, we present a comparative study on soil properties existing in soil and forest farms of Fiji Island. Soil samples from 24 different locations were collected from 8 sites based on the heterogeneity and land use of soils, keeping in view the variation in soil type and slope to determine physicochemical properties and nutrient status. The physical properties such as bulk density (1.05-1.20 Mg m-3), percent porosity (54.14-56.62), moisture % (16.78-18.53%) and soil permeability (11.79-12.35 cm hour-1 was comparatively higher in forest farms compared to the agricultural farms. The soil pH in forest farms and agriculture farms ranged from 5.42-6.10 and 5.30-5.61 respectively. A higher range of CEC was found in forest farms (17.7-19.2) may be due to the higher amount of soil organic matter in forest farms in comparison to agricultural farms. The results also showed that the nutrients such as N, P, K, Ca and Mg and micronutrients (Cu, Fe, Mn and Zn) values were low on the agricultural farms. The study suggests the combined use of good agricultural practices, limited use of agrochemicals and minimal soil disturbance at agriculture farms to prevent further degradation, acidification and nutrient stocks.

Effects of Different Types of Soil Management on Organic Carbon and Nitrogen Contents and the Stability Index of a Durum Wheat–Faba Bean Rotation under a Mediterranean Climate

Soil quality, nitrogen, and organic matter content are increasingly being researched due to their impact on the environment. We assessed the effects of different soil management practices on the distribution and accumulation of soil organic carbon (SOC) in a durum wheat–faba bean rotation system cultivated in a Mediterranean-type area of Southern Italy, over six years. The effects of three levels of soil disturbance—conventional tillage (CT), minimum tillage (RT), and no tillage—(NT) on the SOC and nitrogen (N) content at soil depths of 0–15, 15–30, 30–60, and 60–90 cm were compared in a long-term experiment starting in the 2009–2010 growing season. The three soil management systems showed significant differences (p &lt; 0.05) in the surface layer (0–15 cm depth) in SOC content and total nitrogen, with the largest accumulation occurring in the conservation system (NT). In the deep layers (30–60 and 60–90 cm), however, no significant differences were found between the three tillage systems. The ascending order of the tendency to accumulate SOC and N in the soil in the 0–15 cm layer was NT &gt; CT &gt; RT. In addition, the C/N ratio showed a more equilibrated rate in the NT system. The conservation tillage (NT) gave the best results in terms of the physical characteristics of the soil, showing a higher stability index compared to CT and RT. Conservation tillage is therefore recommended for wheat cultivation in the dry areas of Southern Italy, due to its benefits in terms of both crop yield improvements and environmental protection.

Influence of Conservation Agriculture on Durum Wheat Grain, Dough Texture Profile and Pasta Quality in a Mediterranean Region

There is a growing interest in the Mediterranean regions to switch to conservation agriculture (CA) to address climate change and soil deterioration issues. The novelty of this study lies in the quality of the supply chain, from the raw material (durum wheat grain) to the ready-to-sell product (spaghetti), under long-term CA, and using two varieties over two years of study. This study aims to investigate the impact of two soil management systems (SM) (CA after 10/11 (since 2009–2010) years switching vs. conventional tillage (CT)) on grain quality, dough texture profile, and pasta quality of two Tunisian durum wheat varieties (Karim and Monastir) in a 2-year-long experiment (2019 and 2020). The results showed that the SM had a significant impact on the grain quality in both years in terms of protein content and wet gluten, which were, respectively, lower under CA (11.92% vs. 11.15% for protein content) and (18.75% vs. 17.68% for wet gluten) in the wet year. These parameters increased in the dry year but they were higher under CA (15.70% vs. 14.42 ± 0.94% for protein content) and (26.00% vs. 23.20% for wet gluten). These results have, in turn, affected the dough quality (springiness, chewiness, and cohesiveness) and pasta cooking time and decreased the pasta cooking loss and water absorption index. In terms of the variety (V) factor, “Karim” variety in the dry year had a higher protein content and better dough quality than “Monastir” variety, and it reduced the pasta cooking time. In addition, the pasta yellow index (b*) from grains grown under CA was always higher than those in the CT system (23.99 vs. 19.72% and 25.24 vs. 22.19% in 2019 and 2020, respectively). The interaction between SM and V was significant in both years only for the dough hardness and pasta b* parameters. In conclusion, long-term CA may be a crucial solution in the dry season to promote food quality and achieve sustainable agriculture goals.

Shifting Long-Term Tillage to Geotextile Mulching for Weed Control Improves Soil Quality and Yield of Orange Orchards

Weed control in urban and peri-urban orange orchards is challenging due to operational and legislative restrictions. Tillage, besides from negatively affecting soil fertility and microorganisms, is demanding for humans. On the other hand, herbicides are advised against due to the possibility to reach waterbodies from the soil surface. Therefore, in urban and peri-urban areas, instead of tillage and herbicides, mulching with black plastic geotextile fabric is often used. This study aimed at assessing the impact of long-term soil mulching with black plastic geotextile fabric on soil fertility, microbial community and yield of an orange orchard in comparison to conventional tillage. To this aim, four soil management systems were set up: rotary tillage for the last 15 years, mulching with black plastic geotextiles for the last 15 years, rotary tillage for 7 years followed by mulching for the last 8 years, mulching for 7 years followed by rotary tillage for the last 8 years. Soil samples were analyzed to determine the chemical and biochemical parameters related to soil fertility. In addition, the abundances of the main microbial groups were investigated. Mulching increased soil total organic C at least by 65%. The greater soil organic C in mulched soil in turn contributed to increase the cation exchange capacity (+62% on average) and microbial biomass C (+120% on average). Additionally, the microbial quotient exhibited higher values in mulched soils compared to tilled ones, suggesting a greater soil organic matter accessibility by soil microorganisms. Moreover, mulching favored fungi over bacteria, and Gram-positive bacteria over Gram-negative bacteria, thus contributing to the establishment of a microbial community more efficient in utilizing C sources. The latter result was confirmed by the lower values of the metabolic quotient in mulched soil compared to tilled one. Overall, the black plastic geotextile fabric improved chemical and biochemical soil fertility that, in turn, lead to a higher orange yield in mulched soil.

Physiological Quality of Soybean Seeds as a Function of Soil Management Systems and Pre-Harvest Desiccation

Soil management systems directly interfere in the soil–plant relationship. However, there are still few studies evaluating the influence of long-term management systems on the physiological quality of soybean seeds. Another little-known topic is the influence of pre-harvest desiccation on the physiological quality of soybean seeds, especially on seed longevity. Thus, the aim of this research was to evaluate the physiological quality of soybean seeds cultivated under conventional tillage and no-tillage systems with and without desiccant use. The experiment was carried out in design is a split plot in a randomized complete block design. The treatments consisted of soil management systems (conventional tillage and no-tillage), with and without pre-harvest desiccation. In the treatment with desiccation, the herbicide Paraquat was applied, when the plants were at the R7.3 phenological stage (most of the seeds had a yellowish coat, with a shiny surface and were already detached from the pod). Seed germination, vigor (first germination count, seedling dry mass, seedling length, time to reach 50% germination (T50), seedling emergence and emergence speed index) and longevity (P50) were evaluated. Seeds cultivated under conventional tillage showed greater vigor for most traits evaluated, with values of T50 and seedling length higher by 24.39% and 24.77%, respectively, compared to NT. In addition, non-desiccation increased the seedling length and dry mass, in 15.45% and 21.59%, respectively. The use of desiccant aiming at seed vigor is dependent on the soil management system. Soybean seed longevity was superior in the no-tillage system, but desiccant application reduced seed longevity.

Productivity and technological quality in sugarcane ratoon under subsoiling between planting rows in the northeast region of Brazil

Different soil management systems can change the sugarcane yield and quality parameters for sugar/ethanol production. The objective of this study was to evaluate the effects of subsoiling on the inter-row of sugarcane ratoons after the second harvest on productivity and technological quality. Productivity was estimated in tonnes of sugarcane per hectare (TSH), and technological quality parameters were apparent sucrose percentage (Pol) and total sugar recoverable per hectare (TRS). The apparent sucrose percentage and total recoverable sugar were measured in tonnes per hectare, corresponding to the parameters TSH and total recoverable sugar in tonnes per hectare (TTRSH), respectively. This research was carried out at the Experimental Sugarcane Station at the Federal Rural University of Pernambuco in the northeast region of Brazil. A randomized complete block design was used, with two treatments: conventional tillage and inter-row subsoiling. Subsoiling provided a significant gain of stalk yield of 5.53 tonnes per hectare. The other parameters evaluated did not differ significantly.

Dinâmica da decomposição da matéria orgânica vegetal em diferentes paisagens agrícolas

ABSTRACT The functioning of ecosystems or agroecosystems is mainly dependent on the soil-litterfall interaction. Thus, the objective of this work was to evaluate the effect of different soil use and management systems on the dynamics of decomposition of plant residues of Azadirachta indica (neem) and Gliricidia sepium (gliricidia). The study was conducted in four land occupation systems, namely: remaining forest, agroforestry, agricultural mandala, and pasture. The decomposition rate was estimated using nylon bags (litter bags), containing 20 g of leaves of A. indica and G. sepium, which were arranged on the soil surface of each area for 18, 36, 54, 72, 90, and 108 days. A completely randomized design was used for each species, considering each area as one treatment, with four replications for each collection. The data were subjected to regression analysis and the means were compared by the Tukey's test (p&lt;0.05). More than 85% and 90% of A. indica and G. sepium plant matters, respectively, had been decomposed after 108 days, regardless of the system evaluated, denoting that these species present high decomposition rates. The phytomass half-life time varied from 16 to 23 days for G. sepium and from 25 to 37 days for A. indica, depending on the land use system. Edaphic temperature, soil water content, and leaf physical and chemical characteristics are weight loss predictors. The results provide important information to enable forest management practices.