Mulch Layer Research Articles

Modeling the effects of the plastic-mulched cropland over the arid and semi-arid areas of China on the East Asian regional climate

Arid and semi-arid areas of Northwest China are extremely sensitive to climate change. Plastic mulch is a technology used worldwide to inhibit soil evaporation and increase crop yield. The properties of plastic film are significantly different from the soil. Plastic mulch not only alters the physical attributes of the underlying surface, but also blocks the energy and mass exchanges between the land surface and the atmosphere. This latter situation has not been depicted in current regional climate models. This study couples a detailed plastic mulch layer submodel considering the effects of the plastic mulch on the radiation and heat transfer into the regional climate model RegCM4.5 to explore the effects of plastic mulch on East Asian regional climate over Northwest China. Results suggest that the plastic film covering cropland can enhance the near surface sensible heat transfer, accelerate the rise of near surface air temperature, and reduce the water vapor supply of convective process. Meanwhile, the rainfall is reduced in Northwest China and most areas south of the Yangtze River, while the precipitation is improved from Sichuan and Chongqing to North and Northeast China when the cropland underlying surface is covered by the plastic film. Moreover, the cyclone of the lower troposphere in Northwest China is strengthened and the air pressure is weakened, which promotes the subtropical high to the northwest, thus East Asian summer monsoon is influenced because of the plastic film mulching.

ЭФФЕКТИВНОСТЬ ИСПОЛЬЗОВАНИЯ ОКУЧИВАЮЩИХ РАБОЧИХ ОРГАНОВ С МУЛЬЧИРУЮЩИМ РЕАКТИВНЫМ УСТРОЙСТВОМ В ГРЕБНЕВОЙ ТЕХНОЛОГИИ ВОЗДЕЛЫВАНИЯ КАРТОФЕЛЯ

An analysis of machines and equipment for hilling potato plantings is given, the timing of technological hilling operations is considered, starting from the pre-emergence period until the tops are closed in ridges and rows. The geometric shapes of the bed during the process of hilling potatoes are considered in the form of drawings according to the phases of development and height of the plants. To implement the task, a Hiller with a device for mulching the surface of the ridge is proposed, which allows you to keep the tuberous nest from overheating in hot weather, destroy germinating weeds and retain moisture in the ridge, it is proposed to be used to implement the task. This is a hiller with flaps, behind the body of which grinding devices are installed in the form of rotating disks with blade fingers mounted on an axis. A rod with a spring for copying the surface of the ridge by the mulching device is installed at an angle in the flaps of the hiller body with a pitch equal to twice the diameter of the fingers of the chopping device. It is noted that the use of the proposed hilling device makes it possible to perform interrow cultivation in one pass, combine the operation of destroying the pruned soil layer and crushing it, destroying weeds and mulching the surface of the ridge. The results of a study of the use of an experimental hiller in practice show that in the created fine-lumpy ridge layer from the soil, it is saturated with air oxygen, which accelerates the anaerobic and aerobic processes occurring in it, contributing to the accelerated decomposition and mineralization of soil organic matter. A comparison of the performance indicators of serial and experimental hillers has been carried out. It has been established that the experimental hiller allows the cultivator to operate at increased speeds of up to 2.6 m/s and to create a cover of the ridge with a mulching layer of soil of 3–4 cm, with the size of lumps on the surface layer of the ridge of 1–1.5 cm, to destroy weed seedlings in comb up to 95%. During the research, it was found that the effectiveness of the introduction of an experimental hiller will increase potato yields by 5-7%.

Recurring Rolling/Crimping Effects on Termination Effectiveness of Iron Clay Pea and Pearl Millet Warm-Season Cover Crops

Summer cover crop utilization by no-till vegetable farms is essential for continuous soil protection, especially in the southern United States where intense storms are likely to occur in hot and humid summer months. A field experiment was conducted at the National Soil Dynamics Laboratory in Auburn, AL, USA, between the summers of 2015 and 2017 to determine the effectiveness of an experimental roller/crimper in mechanically terminating summer cover crops. Iron clay peas (Vigna unguiculata, L.) planted on a sandy loam and pearl millet (Penninsetum glaucum, L.) planted on clay soil were selected to determine termination rate effectiveness in single, double, and triple rolling/crimping over the same area. Overall, termination rates for both cover crops were higher for rolling three times (71%) compared to rolling once (55%) or twice (63%). However, cover crop termination was inhibited due to rainfalls on the experimental area during the three-week evaluation period. In 2016, drought conditions and high temperatures (32.6 °C) caused biomass reduction, especially for pearl millet, of over 31% to 39% compared to 2017 and 2015. Rolling provided higher soil-water conservation compared with the non-rolled control due the cover crop mulch layer blocking sunlight, keeping the soil surface cooler and preventing water evaporation. Recurrent rolling did not cause soil compaction above the 2.0 MPa level that inhibits root growth, but changes in soil strength were dependent on the soil moisture content.

INFLUENCE OF AGRICULTURAL PRACTICES ON THE PROCESS OF SOIL FREEZING

Only the change in soil temperature with time has been systematically studied on different types of soils. At the same time, many agricultural practices aim to regulate the soil’s temperature regime. Thus, snow retention and mulching with plant residues are effective measures aimed at increasing the temperature of the surface layers of the earth. In the article, the authors investigated the process of world freezing with a mulched surface under a layer of snow covered with an ice crust. Methods of theoretical analysis (structuralfunctional, systemic approach) and mathematical statistics are used. The authors conducted field studies in two versions at LLC “Plemsovkhoz” Kenzhe “of the Kabardino-Balkarian Republic. The first option is bare soil, and the second option is mulched soil with the creation of an ice crust on the snow surface in winter. Studies were carried out on the influence of the mulching layer of vegetation and the ice crust on the snow surface on the annual variation in soil surface temperature and soil temperature. These study results indicate that mulching the soil surface with plant residues and creating an ice crust on the snow surface contributes to the “smoothing” of the soil temperature. So, when using the proposed technological methods, the temperature of the soil with a change in depth from 0 to 100 cm changes from 0°С to +2.5 °С, while without their use - from -3 °С to +2 °С. The authors proved that the temperature of the soil at a depth of 30 cm, when using the proposed technological methods, reaches above 0 °C. This confirms the effectiveness of these techniques in preventing dirt freezing.

Soil Erosion in Extensive versus Intensive Land Uses in Areas Sensitive to Desertification: A Case Study in Beira Baixa, Portugal

The occurrence of long periods of drought followed by extreme episodes of rainfall and ineffective soil conservation practices are the main causes of soil erosion in the Mediterranean region. The objective of this paper is to assess and compare the hydrological and erosional responses related to land use changes in agricultural landscapes that are sensitive to erosion and that are a result of the significant replacement of traditional land uses. Such changes are characterized by the replacement of extensive olive groves associated with pastureland by intensive almond production, where deep plowing and heavy machinery are required. In each sampling site, runoff initiation, runoff coefficient, and soil loss were evaluated under simulated rainfall (55 mm h−1), at plot scale (0.25 m2), at the end of the hot and dry summer period. Slope gradient, soil texture, bulk density, soil organic matter content, soil water content, and plant cover were also determined. The results showed the impact of recently planted intensive almond orchards (IAOs) on accelerating soil erosion risk compared with the extensive traditional olive groves (EOGs), although runoff initiation and discharge are very similar between the studied land uses. The mean values recorded for soil loss and sediment concentration were 118 g m−2 h−1 and 12 g m−2 h−1 and 3.1 g L−1 and 0.7 g L−1, respectively, for IAOs and EOGs. Our results also demonstrated that maintaining a vegetation cover is a determining factor for the prevention and control of soil erosion, especially in IAOs, where retaining high percentages of natural plant-residue mulch layers (>70%) reduced soil loss by about 70% in this study.

The effect of layers of high tunnel covering and soil mulching on tomato fruit quality.

High tunnels (HT) and plastic mulch can increase yield, extend growing seasons, protect plants from harsh weather conditions, and produce more marketable and attractive tomatoes. However, plastic covering reduces solar radiation, which may affect the quality of tomatoes. This study investigated the effects of single-layer versus double-layer HT and plastic mulch versus bare soil on the quality of fully ripe tomato fruits. The study was conducted over 2 years (2021 and 2022). The fruit color (L*, a*, and b*), vitamin C, pH, total titratable acid (TTA), total soluble solids (TSS), and lycopene content of the two tomato cultivars (Brandywine and Rebelski) were quantified. The results showed that quality parameters varied with the plastic layers of HT, plastic mulch, and planting year. The double-layer HT only showed a slight but significant influence on the color of tomatoes of both cultivars in the same year (P < 0.05). Brandywine tomatoes grown in the double-layer HT had significantly lower pH and lycopene content than those grown in single-layer HT, regardless of mulching. The effect of plastic layers on TTA, TSS, and lycopene depended on whether the soil was mulched. Tomatoes grown on bare soil had higher TTA and TSS values than those grown on mulched soil in double-layer HT. Tomatoes grown in single-layer HTs had significantly higher vitamin C content than those in the double-layer HT for both cultivars regardless of mulching. This study demonstrates that double-layer HT is unnecessary for the improvement of the overall quality of tomatoes. © 2023 Society of Chemical Industry.

The Influence of Soil Decompaction and Amendments on Soil Quality

Abstract Urban soil is often compacted during anthropogenic activities, which presents a challenging substrate for tree growth. Two techniques for decompacting soils (air spading and vertical mulching) were evaluated alone and in combination with the soil amendment biochar and/or a woodchip mulch. Effects on soil quality (bulk density, organic matter, vegetation ground cover, cotton strip degradation, root dry mass, and earthworm counts) were monitored over 5 years. A combined treatment of air spading, biochar, and a woodchip mulch layer proved optimal in improving the soil quality of a heavily compacted soil over the 5-year period. This treatment was, however, the most expensive and time-consuming. A woodchip mulch was the most effective of the individual treatments and the most cost-effective. Air spading alone proved reasonably effective in improving soil quality over the 5-year study period. Effects of air spading could be improved by addition of a woodchip mulch. Vertical mulching alone or in combination with biochar had little influence on soil quality over 5 years. Results demonstrated that effective long-term soil decompaction measures exist for arborists to improve compacted soils.

Light to moderate long-term grazing enhances ecosystem carbon across a broad climatic gradient in northern temperate grasslands

Grasslands are globally abundant and provide many ecosystem services, including carbon (C) storage. While grasslands are widely subject to livestock grazing, the influence of grazing on grassland ecosystem C remains unclear. We studied the effect of long-term livestock grazing on C densities of different ecosystem components in 110 northern temperate grasslands across a broad agroclimatic gradient in Alberta, Canada. These grasslands stored 50 to 180 t ha−1C in live and dead vegetation, as well as soil C to 30 cm depth, with the majority as soil organic C (SOC). The mulch layer comprised a large amount of C (~18 t ha−1C) especially within humid grasslands. Although grazing reduced C densities in litter mass, total ecosystem C was 8.5 % greater under grazing (127.8 t ha−1) compared to those non-grazed (117.8 t ha−1), primarily due to increases in SOC and roots. Increases in SOC were consistently observed in the 0–15 cm layer across all climatic conditions, with changes in SOC of the 15–30 cm layer inversely related to aridity. A structural equation model revealed that increased SOC under grazing was indirectly attributed to increases in eudicot rather than graminoid biomass. In addition, SOC increased with graminoid quality (i.e., a reduced carbon to nitrogen ratio), which together with elevated eudicots, increased litter and mulch C, and ultimately enhanced SOC densities. When applied to spatial maps of habitat type and land use (livestock grazing) activity across the region, an area of ~3.8 M ha of grassland was projected to contain an additional 17.1 M t of C under grazing, primarily in mesic grasslands, worth an estimated $3.1 B (Cdn.) under current C valuation guidelines in Canada. Overall, these results highlight the importance of grasslands for C storage and establishing policies that maintain and promote their sustainable use, including light to moderate grazing.

Аgrophysical state of podzolized chernozem in agrocoenosis during the different types of transition to no-till technology

Aim. To scientifically substantiate the significance of the transition period after the abandonment of plowing and the transition to the No-till system for changing the agrophysical conditions of fertility, as the basis for optimizing the regime of moistening of chernozem of podzolized highly regraded low-humus soil in a 5-fold grain rotation for the conditions of the Central Forest Steppe of Ukraine. Methods. Field, agrochemical (selection of samples and determination of total humus, structure density, structural state, in the 0-30 cm layer of the soil, productive moisture reserves of a meter thick, statistical and calculation (to justify the reliability of the obtained results and develop statistical models of relationships).. The research was carried out in a stationary field experiment of the Cherkasy State Agricultural Research Station of the NSC “Institute of Agriculture of the National Academy of Sciences”. Results. When abandoning plowing per unit increase in the density of the structure, the optimization of the ratio of gaps occupied by moisture to air (1 to 1) increases under No-till systems by plowing in 1.81 times, for surface tillage - 1.98 times, and for No-till systems for surface tillage - 2.68 times. Implementation of the No-till system for surface tillage formed an average reserve of productive moisture in the crop rotation at the level of 154 mm, which was at the level of stock on plowing and significantly higher than under systematic surface cultivation. Deviation from the average o the value of the moisture reserve under the component crops was the lowest compared to systematic plowing, the No-till system after plowing and surface treatment and systematic surface treatment, which is associated with the optimization of the agrophysical properties of the 0-30 cm soil layer and the presence of a layer of plant mulch on the soil surface from predecessors. Conclusions. When switching to the No-till system in a 5-field grain rotation, it is necessary to apply a transition period with soil-protective shallow tillage, which in 5 years helps to overcome the manifestation of agrophysical degradation of podzolized chernozem due to the reproduction of the humus, structural state and water resistance of the structure, will ensure the achievement of an equilibrium state of density structures, the most optimal ratio of the volume of cracks occupied by moisture to air, which will provide a mechanism for regulating the consumption of the productive moisture reserve for physical evaporation compared to systematic plowing and the No-till system for plowing where the manifestation of agrophysical degradation remains at a high level.

Excessive Nitrate Limits the Sustainability of Deep Compost Mulch in Organic Market Gardening

Market gardening is a widespread practice of bio-intensive vegetable production characterized by direct marketing, small-scale farming structures, high crop densities, and innovative cultivation approaches. Currently, deep compost mulch (DCM) is a popular trend among related growing techniques. The combination of no-till and a permanent mulch of compost aims to improve soil fertility, regulate soil temperature, retain soil moisture, and control weeds. To address the problem of perennial weeds in organic no-till, deep mulch layers of typically 150 mm are used. The amount of compost required and the associated N inputs are immense and carry the risk of environmentally harmful N surpluses that can be lost through nitrate leaching or denitrification. The aim of this study is to evaluate the use of compost as mulch and to investigate N dynamics under DCM. For this purpose, a literature review was conducted, and soil inorganic nitrogen (Nmin-N) was measured under on-farm conditions up to a soil depth of 900 mm in a market garden with DCM in Germany for one year. Furthermore, based on the collected data, the different N pathways were calculated using the N-Expert and NDICEA models and simulated for two additional scenarios. Results from field measurements showed a strongly increased N-surplus not taken up by the crops and a shift of Nmin-N to deeper soil layers for municipal organic waste compost (MW), with an average accumulation of 466 kg Nmin-N ha−1 at 600–900 mm depth. N inputs from DCM can be significantly reduced by the use of green waste compost (GW) with low bulk density or wood waste compost (WW) with an additional high C/N ratio.

Does wood mulch trigger microbially mediated positive plant-soil feedback in degraded boreal forest sites? A post hoc study.

Reforestation of degraded lands in the boreal forest is challenging and depends on the direction and strength of the plant-soil feedback (PSF). Using a gradient in tree productivity (null, low and high) from a long-term, spatially replicated reforestation experiment of borrow pits in the boreal forest, we investigated the interplay between microbial communities and soil and tree nutrient stocks and concentrations in relation to a positive PSF induced by wood mulch amendment. Three levels of mulch amendment underlie the observed gradient in tree productivity, and plots that had been amended with a continuous layer of mulch 17 years earlier showed a positive PSF with trees up to 6 m tall, a closed canopy, and a developing humus layer. The average taxonomic and functional composition of the bacterial and fungal communities differed markedly betweenlow- and high-productivity plots. Trees in high-productivity plots recruited a specialized soil microbiome that was more efficient at nutrient mobilization and acquisition. These plots showed increases in carbon (C), calcium (Ca), nitrogen (N), potassium (K), and phosphorus (P) stocks and as well as bacterial and fungal biomass. The soil microbiome was dominated by taxa from the fungal genus Cortinarius and the bacterial family Chitinophagaceae, and a complex microbial network with higher connectivity and more keystone species supported tree productivity in reforested plots compared to unproductive plots. Therefore, mulching of plots resulted in a microbially mediated PSF that enhances mineral weathering and non-symbiotic N fixation, and in turn helps transform unproductive plots into productive plots to ensure rapid restoration of the forest ecosystem in a harsh boreal environment.

Response of soil respiration to hydrothermal effects of gravel–sand mulch in arid regions of the Loess Plateau, China

Gravel–sand mulching is a traditional no–tillage technique used for more than 300 years on the Loess Plateau. Applying gravel–sand mulch (mixture of gravel and sand) has an impact on the soil environment, soil microorganisms, and crop yield. However, we know surprisingly little of how respiration dynamics at the soil surface is affected by gravel–sand mulching. To study the response of soil respiration (Rs) dynamics to different in gravel–sand mulch thickness and its driving factors, we recorded Rs under a gradient of gravel–sand mulch thickness consisting of six layers (0 cm [CK], 3 cm, 5 cm, 7 cm, 9 cm, 11 cm), in situ, during the growing season by using the LI–6400–09 soil respiration measurement system on the Loess Plateau in northwest China. The trends of all six treatments in diurnal and monthly variation of soil respiration followed a single–peaked curve; the diurnal dynamics trends were consistent with soil temperature changes. With gravel–sand mulch applied, the daily peak of soil respiration decreased, and the peak in Rs under the gravel–sand mulch treatments lagged that of bare land by 2 h. Monthly changes in soil respiration were consistent with soil temperature and precipitation changes, with peaks concentrated in July and August. Compared with bare land (CK), the monthly average soil respiration is lowest at 0.67 µmol∙m–2∙s–1 under a 11–cm thick mulch layer, and reduced by 26.63–61.03% by all mulch applications. Gravel–sand mulch reduced the temperature sensitivity of soil respiration, while soil temperature and soil water content were the main factors determining soil respiration. The thickness of gravel–sand has a significant, negative exponential function relationship with the changes in monthly soil respiration. Further, compared with bare land, the presence of gravel–sand mulch reduced the positive impact of precipitation on Rs. Soil temperature (T), gravel–sand mulch thickness (M), and soil pH were all significant predictors of soil respiration (Rs) (multiple regression model: Rs = 8.561 + 0.077 T – 0.056 M – 0.989 pH), together accounting for 73% of its variation. Hence, by considering all these three factors simultaneously we can better explain the changes to soil respiration in response to gravel–sand mulch. Overall, our results show that as the thickness of the gravel–sand layer increases, soil respiration decreases.

Water dynamics of cover crops: No evidence for relevant water input through occult precipitation

AbstractRising temperatures and disruption of rainfall patterns due to climate change make water a limiting growth factor even in regions of temperate climates. Thus, producing ‘more crop per drop’ is of utmost importance. While cover crops provide many benefits to cropping systems, their influence on soil water is discussed controversially. While an increase in transpiration can lead to soil water depletion, the reduction of evaporation in combination with possible additional water inputs could provide a water benefit for a succeeding crop. Occult precipitation could be such an additional water input. The objective of this study was to quantify whether cover crops provide a net water benefit over a bare fallow due to the occurrence of occult precipitation. In a 2‐year experiment, seven different cover crops were cultivated in pure stands and as a mixture under semi‐controlled conditions in a container experiment. Water fluxes and meteorological conditions were closely monitored. Although favourable conditions occurred during both vegetation periods, we found no evidence of occult precipitation. In autumn, soil water was depleted by fast‐growing cover crops. In winter, soil water was recharged due to the early preparation of a mulch layer combined with high winter precipitation while in early spring rising temperatures increased transpiration losses of a winter‐hardy cover crop, leading to a reduction of soil water. For middle European conditions, this shows that (1) living cover crops do not provide any water benefits and that (2) soil water recharge in winter is highly dependent on meteorological conditions and cover crop management. From a water budget viewpoint, negative effects on a succeeding cash crop can only be prevented if cover crops are terminated early enough for replenishment of soil water.

Coarse pine bark mulch as open surface cover fails to improve establishment of sown native grasslands

SummaryThis study was conducted across twelve agricultural locations in south‐western Victoria, Australia, encompassing a range of soil types and climatic conditions. It investigated the addition of an open layer of coarse organic pine wood chip mulch (~70% surface cover) directly following direct seeding of native grassland species. The intent was to mimic positive effects of naturally occurring organic surface litter (which are typically depleted in such settings) on seedling emergence and establishment. Findings revealed negative results in that the use of an open layer of coarse pine chip mulch failed to improve native establishment at 12‐months or to moderate soil temperature and moisture extremes in comparison to non‐mulched plots. This outcome suggests the effectiveness of open surface mulches under the scenario of direct seeding may be highly site context, mulch‐type, and application approach dependent. In situations where such mulch applications are not likely to be beneficial, significant costs relating to their purchase and application could be avoided.

Изменение гидротермических условий в пахотном слое чернозема при мульчировании резаной соломой

The research goal was to study the trends in the influence of the mulching layer of cut straw on the change in hydrothermal conditions of the arable soil layer. The object of study was one of the most common soils of the Altai region – leached loamy chernozem. The plots for the experiment were laid on a steam field. One of the sections was mulched on the surface with a layer of cut straw 10‑15 mm thick, on the other section the mulch layer was 20‑25 mm. The third section of the black vapor was used for contrast control measurements. According to the measurements, it was revealed that in the mulched observation areas there was a noticeable decrease in soil temperature during the daytime both on the surface and in the entire arable layer compared to the control one. At night, a layer of cut straw prevented a sharp change in temperatures and contributed to the preservation of heat. The thickness of the mulching layer determined the temperature values of the arable layer during the daytime and at night. A layer of mulch on the soil surface contributed to the preservation of soil moisture reserves in the arable soil horizon. With an increase in the size of the mulching layer, there was a tendency for better moisture retention. The use of mulching of the surface layer of the soil with cut straw is advisable in arid regions to reduce the absolute values of the temperatures of the arable layer and reduce the evaporation of soil moisture from its surface, as well as to preserve moisture in the arable horizon of the soil.

ROTARY MOWER FOR TREATING NEAR-STEM STRIPS OF FRUIT PLANTATIONS ON TERRACES

One of the problems faced by producers in the conditions of slope gardening is the lack of specialized equipment suitable for carrying out the necessary work related to the care of the trunk strips of fruit trees. The design features of the terraces impose restrictions on the operating conditions of agricultural aggregates, among them it is necessary to highlight the possibility of approaching the row line for processing plants from only one side. Most horticultural farms have mainly equipment designed to work in conditions of plain gardening, which is often unsuitable for the care of fruit plantations located on terraces. Research aimed at developing agricultural machinery for processing row spacing and trunk circles of fruit trees in one pass is relevant. (Research purpose) The research purpose is substantiating the main design parameters and operating mode of the mower for mowing vegetation from the space around the stem of the fruit tree without damaging the latter in one pass. (Materials and methods) Used the results of the functioning of technical means in the conditions of mountain gardening through logical analysis. We conducted theoretical studies using the well-known laws of mathematical analysis and theoretical mechanics. (Results and discussion) We examined the operation of the cutting machine of the mower in the process of mowing vegetation in the area of the trunk circle. (Conclusions) A prototype mower was manufactured, production tests of which (at a movement speed of 1.89 kilometers per hour, the number of rotors with cutting segments of 2 pieces, the length of the cutting segment of 42 millimeters, the rotation speed of the rotors of 2000 minutes minus the first degree) confirmed that it with a capacity of 0.36 hectares per hour provides mowing vegetation from the space around the stem of the fruit tree without damaging the latter in one pass. It was determined that due to the creation of a mulching layer, the soil condition is improved, terraces are protected from erosion processes and unit costs are reduced.

The Effect of Mulch Materials on Selected Soil Properties, Yield and Grape Quality in Vineyards under Central European Conditions

The results of this study provide overall information on the verification of the effect of applying two different mulching materials of an organic origin to the soil surface in the area between rows of grape vines in vineyards on selected physical and chemical properties of the soil and, at the same time, on the yield and quality parameters of the grape vines (Vitis vinifera L.). During the period under study, 2018–2020, the effect of shredded cereal straw (CS) and compost from garden waste (CO) was investigated. The control variant (CWC) was left without any cover and was regularly cultivated with a coulter cultivator to a depth of 60 mm. During the experiments, meteorological data were monitored and recorded along with soil temperature and soil moisture for each variant. The results show that the lowest temperature was measured for the straw cover variant (11.10–11.87 °C), while the highest soil temperature was measured for compost (11.93–13.16 °C). Under the straw, the moisture level in the soil was higher compared to the other variants, and there was a gradual increase (of 3%) in soil bulk density values compared to the baseline. By contrast, the compost variant showed a decrease (of 1%) in bulk density values. The differences in nutrient content were slight among the variants. The only statistically significant difference was identified for the compost variant with respect to the content of total nitrogen and phosphorus. Further results demonstrated a positive effect of both mulch material variants on grape yield, which was 6–19% higher in the variants with a cover layer. In addition, the use of mulch also had a positive effect on grape quality. For example, the sugar content—one of the main quality parameters—increased by 1–7% due to the mulch layer. Based on these results, the use of mulching materials can be recommended for areas with low total rainfall during the growing season, as well as when growing varieties with irregular yields and uneven grape quality.

KONTRIBUSI TANDAN KOSONG DALAM MENINGKATKAN PENGARUH PUPUK ANORGANIK TERHADAP PRODUKSI KELAPA SAWIT

Sustainable intensification of oil palm plantations faces the challenge of decreasing soil fertility and increasing the price of inorganic fertilizers. Organic matter plays an important role in maintaining soil fertility. Empty fruit bunches (EFB) are the main co-product of palm oil mills that have the potential to be used as a source of organic matter and nutrient sources. This study aims to reveal the effect of the application of empty fruit bunches in increasing the effectiveness and substituting inorganic fertilizers for the components of oil palm production. The number of female inflorescence, the number of FFB and the average weight of FFB were observed for 3 years on palm aged 8, 9 and 10 years. Application of EFB + 70% recommended inorganic fertilizer. The recommended fertilizer is 8 kg per tree (N P K Mg 14-28-6-2 +0.5 B). EFB are applied as one layer of mulch with a size of 3x4 m on a dead net. The results showed that the application of empty bunches could increase the number of female flowers and the number of FFB in plants aged 9 and 10 years (1-2 years after application), while inorganic fertilizer EFB was only at the age of 8 years (0 years after application) for both production components. FFB weight one year after application of EFB+70% inorganic fertilizer (age 9 years ) was higher than 8 and 10 year aged plants. The application of EFB+70% inorganic fertilizer can increase the contribution of nutrients from fertilizers compared to the application of inorganic fertilizers solely.

Corncob-pyrite bioretention system for enhanced dissolved nutrient treatment: Carbon source release and mixotrophic denitrification

Solid biomass waste amendment and substrates modification in bioretention systems have been increasingly used to achieve effective dissolved nutrients pollution control in stormwater runoff. However, the risk of excess chemical oxygen demand (COD) leaching from organic carbon sources is often overlooked on most occasions. Pyrite is an efficient electron donor for autotrophic denitrification, but little is known about the efficacy of autotrophic-heterotrophic synergistic effect between additional carbon source and pyrite in bioretention. Here, four bioretention columns (i.e., corncob column (C), pyrite column (P), the corncob-pyrite layered column (L-CP), and the corncob-pyrite mixed column (M-CP)) were designed and filled with soil, quartz sand, and modified media to reveal the synergistic effects. The results showed that the corncob-pyrite layered bioretention could maintain low COD effluent concentration with high stability and efficiency in treating dissolved nutrients. When the influent nitrogen and phosphorus concentrations were 8.46 mg/L and 0.94 mg/L, the average removal rates of ammonia nitrogen, total inorganic nitrogen, and phosphate were 83.6%, 70.52%, and 76.35%, respectively. The scouring experiment showed that placing the corncob in the mulch layer was beneficial to the sustained release of dissolved organic carbon (DOC). Erosion pits were found in the SEM images of used pyrite, indicating that autotrophic denitrifying bacteria in the bioretention could react with pyrite as an electron donor. The relative abundance of Thiobacillus in the submerged zone of the corncob-pyrite layered bioretention reached 38.39%, indicating that the carbon source in the mulch layer increased the relative abundance of Thiobacillus. Coexisting heterotrophic and autotrophic denitrification in this bioretention created a more abundant microbial community structure in the submerged zone. Overall, the corncob-pyrite layered bioretention is highly promising for stormwater runoff treatment, with effective pollution removal and minimal COD emission.

The use of the No-till technology in autumn wheat cultivation in order to increase the capacity of soil water accumulation and the decrease of fuel costs

Traditional agricultural practices, based on intensive soil tillage, have not ensured the sustainable development of agriculture. At the same time, innovative technologies used in agriculture are becoming less efficient or have a short-term effect, causing negative consequences for the environment. In addition, prices for non-renewable energy sources and their derivatives are increasing, which directly affects the stability of the agricultural sector. In this context, a new paradigm of agricultural intensification is needed, based on the conservation of natural resources, the reduction of production costs and the prevention of environmental degradation. The Conservation Agriculture System (CAS) is able to answer these questions by implementing them correctly, respecting all its basic principles: crop rotation, minimal soil disturbance and ensuring an optimal layer of mulch on soil surface. In our experiment the extra yield from conventional soil tillage was equal to the economy of fuel by using No-till technology, without taking in consideration other advantages for No-till.