Nutrient Losses Research Articles

Cover Crop Effects on Surface Runoff and Subsurface Flow in Rainfed Hillslope Farming and Connections to Water Quality

Abstract: Surface runoff and subsurface flow patterns were monitored in hillside runoff plots in almond and olive orchards with soils covered with spontaneous plants over two hydrological years. The experimental runoff plots were located on the south flank of the Sierra Nevada (Lanjarón, SE Spain) at 580 m a.s.l. with an area of 40 m2 (10 m × 4 m). The surface and subsurface discharge were collected and measured at different soil depths (0, 5, 10, 25, and 50 cm), and the dissolved nutrient concentrations (NO3–N, NH4–N, PO4–P, and K) were determined. According to the findings, the subsurface flow pathways drained most of the rainfall water compared with surface runoff, which was affected by plant cover. The influence of rainfall intensity (I30) on surface runoff was more meaningful than that on subsurface flow. Throughout the monitoring period, the runoff coefficients at soil depths of 0, 5, 10, 25, and 50 cm averaged 0.04, 0.11, 0.14, 0.17, and 0.18, respectively. Subsurface flow was one of the dominant pathways for N and K loss, whereas P loss mainly occurred via surface runoff. Moreover, the concentrations in subsurface flow were higher than the recommended level for standard water quality for NO3–N, NH4–N, and PO4–P. Subsurface flow was the main route of dissolved nutrient delivery, making these nutrients available to the root systems of trees, where nutrient uptake is more likely to occur. Thus, by lessening surface runoff and encouraging surface vegetation coverage to facilitate the recycling of nutrients and buffer the rainfall’s impact on the soil surface, nutrient loss control can be achieved.

Response of runoff N and P concentrations, losses, and stoichiometry to rainfall amount category, multisource fertilization, and straw return in sloping croplands

Nitrogen (N) and phosphorus (P) losses via runoff from sloping croplands are a major threat to the degradations of soil fertility and water quality worldwide. Rainfall amount category and agricultural practices, such as multisource fertilization and straw return, are key factors regulating nutrient loss via runoff in sloping croplands. Yet, the impacts of these factors on N and P losses via runoff remain elusive. This study investigated the responses of N and P in runoff to rainfall amount category, multisource fertilization, and the combination of multisource fertilization and straw return in sloping cropland with a radish and maize rotation during multiple natural rainfall events between 2019 and 2021. Three agricultural treatments (three replications for each), i.e., local traditional fertilization (CK), multisource fertilization (T1), and a combination of T1 and straw return (T2), were applied on nine 8 m × 3 m plots. The concentrations and losses of total nitrogen (TN), total phosphorus (TP), dissolved nitrogen (DN), dissolved phosphorus (DP), particulate nitrogen (PN) and particulate phosphorus (PP) and their paired stoichiometries in runoff were determined. The runoff depth during rainstorms was similar to that in large rainstorms and was 191.1 % and 178.7 % higher than in moderate and heavy rains, respectively (p < 0.05). The PN concentration was the highest during moderate rain, and the highest concentrations of TP and DP were observed during large rainstorms (p < 0.05). Rainstorms and large rainstorms produced higher runoff losses for PN, TP, DP, and PP than for other rainfall amount categories (p < 0.05). Compared to CK, the runoff depth was marginally reduced by 4.2 % and 12.7 % in T1 and T2, respectively, and the concentrations and losses of N and P in runoff also slightly increased in T1 and T2. The DN and DP losses accounted for 70.5 % and 59.8 % of the TN and TP losses across all treatments, respectively, indicating that the dissolved forms played a dominant role in nutrient loss via runoff. TN:TP (77:1) in runoff was higher than the Redfield ratio (16:1) across all treatments, implying a stoichiometric potential for P depletion in the runoff. Our results highlight the potential risk of N and P losses in dissolved form via runoff regulated by rainfall, multisource fertilization and straw return in sloping croplands.

Проблемы опустынивания в восточной зоне Ростовской области

The article presents an analysis of the dynamics of soil fertility, trace elements, pH, aridity index and normalized index. Salt lakes in the complex from 30-50 % occupy 68.3 thousand hectares. The humus content in the arable layer is low. There is a decrease in the content of humus (from 2.2% to 1.7%) and phosphorus (from 18.6 mg/kg to 18.2 mg). The content of exchangeable potassium is generally within the optimal range. The processes of loss of humus and nutrients in the soils of the area are a manifestation of the desertification process. The content of sulfur and trace elements (copper, zinc, manganese, cobalt) is low, insufficient for grain crops. The soils of the district are slightly alkaline (pH – 8.1). The aridity index of the Zavetinsky district is 0.41, and the normalized index is 0.59. According to the normalized aridity index – 0.59, the territory of the Zavetinsky district belongs to the moderately arid (NIA =0.5—0.6). Keywords: DESERTIFICATION, SALT LAKES, ARIDITY INDEX, SOIL FERTILITY, TRACE ELEMENTS

Additional organic and bacterium fertilizer input regulated soybean root architecture and dry matter distribution for a sustainable yield in the semi-arid Region of China.

In the dryland area of the Loess Plateau in northwest China, long-term excessive fertilization has led to soil compaction and nutrient loss, which in turn limits crop yield and soil productivity. To address this issue, we conducted experiments using environmentally friendly organic fertilizer and bacterium fertilizer. Our goal was to investigate the effects of additional organic and bacterium fertilizer inputs on soil water migration, crop root architecture, and yield formation. We implemented six different fertilizer strategies, namely: Nm (mulching, N 30 kg/ha), NPK1m (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha), NPK2m (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha), NPKOm (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha; organic fertilizer 2 t/ha), NPKBm (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha; bacterium fertilizer 10 kg/ha), and N (N 30 kg/ha; no mulching). The results revealed that the addition of bacterium fertilizer (NPKBm) had a positive impact on soybean root system development. Compared with the other treatments, it significantly increased the total root length, total root surface area, and total root length density by 25.96% ~ 94.89%, -19.63% ~ 36.28%, and 9.36% ~ 28.84%, respectively. Furthermore, NPKBm enhanced soil water consumption. In 2018, water storage during the flowering and podding periods decreased by 12.63% and 19.65%, respectively, while water consumption increased by 0.97% compared to Nm. In 2019, the flowering and harvest periods decreased by 23.49% and 11.51%, respectively, while water consumption increased by 0.65%. Ultimately, NPKBm achieved high grain yield and significantly increased water use efficiency (WUE), surpassing other treatments by 76.79% ~ 78.97% and 71.22% ~ 73.76%, respectively. Subsequently, NPK1m also exhibited significant increases in yield and WUE, with improvements of 35.58% ~ 39.27% and 35.26% ~ 38.16%, respectively. The use of bacterium fertilizer has a profound impact on soybean root architecture, leading to stable and sustainable grain yield production.

Acceleration of Organic Compost Supply Using Microbial Consortium Formulation on Various Organic Wastes and their Effect on Sweet Corn

Organic waste, primarily originating from agricultural sources, remains underutilized in Indonesia, despite its substantial potential as an organic fertilizer. Consequently, it is imperative to comprehend the technology capable of efficiently decomposing organic matter and yielding high-quality compost. This study aimed to investigate the impact of a microbial consortium compris-ing Bacillus sp., Pseudomonas sp., Trichoderma sp., and Aspergillus sp. on the decomposition of organic waste derived from rice, sugarcane, corn and as well as to examine its application to sweet-corn (Zea mays var. saccharata). The study used a factorial randomized block design, featuring two primary factors, compost types and their respective doses. This design in total of nine treatments, each replicated three times, thus resulting in a sum of 27 experimental units. The treatments were RSC: Rice straw compost; SLC: Sugarcane leaves compost; CHC: Corn husk compost; D7.5: Compost dose of 7.5 t ha-1; D15: Compost dose of 15 t ha-1; D22.5: Compost dose of 22.5 t ha-1. Moreover, an essential fertilizer, NPK, was applied at a rate of 200 kg/ha. The find-ings demonstrated a substantial impact of both compost types and doses on maize growth parameters, which encompassed plant height, leaf area, chlo-rophyll contentand dry weight. These effects were observed individually, without any interactions between the two factors. Furthermore, these treat-ments exhibited a discernible influence on corn yield. The highest to lowest yields were recorded as follows: CHC (9.29 t ha-1), RSC (8.72 t ha-1), and SLC (8.00 t ha-1). Combining organic compost with chemical fertilizer effectively prevented nutrient loss through denitrification and evaporation, facilitating nutrient retention and controlled release over time.

Factors affecting nutrient losses in hay production

AbstractThe primary objective of haymaking is to dry forage adequately to inhibit the growth of undesirable microbes and halt residual plant enzymatic activity that causes nutrient losses. During the field and storage phases of haymaking, the environment, management practices, and other factors influence the extent of dry matter losses. This review discusses these factors and the strategies that have been developed to mitigate nutrient losses. A major emphasis was placed on hay microbiome dynamics, as it has been scarcely studied despite its importance on nutrient losses during storage and harvest, especially under humid conditions. The effects of cutting height, mower type, and swath manipulation on soil contamination were discussed. Also, the impact of environmental conditions and swath manipulation on wilting time was analysed for humid and arid conditions. Special attention was given to design improvements in harvesting equipment to reduce wilting time and field losses. Furthermore, we assessed the nutrient losses during storage caused by microbial and residual plant enzymatic activity resulting from excessive moisture at baling or re‐introduced moisture during storage. The spoilage extent during storage depends on bale moisture, size, density, shape, wrapping, forage type, and storage facilities. A Venn diagram analysis showed that each phase of haymaking process has a unique microbiome and that certain fungal and bacterial genera could be shared across more than one hay production phase. To take corrective actions, hay producers need to be aware of the increased susceptibility to nutrient losses associated with particular field and storage practices, environmental conditions, and forage types.

Intelligent system based on a satellite image detection algorithm and a fuzzy model for evaluating sugarcane crop quality by predicting uncertain climatic parameters

The increase in uncertain weather affects agriculture, impacting crop yield and quality, mainly due to the interaction of climatic variables such as temperature, wind speed, and humidity. In addition, soil erosion and nutrient loss are regional problems aggravated by inadequate agricultural practices in developing sugarcane agriculture. The present research proposes an Intelligent System based on a detection algorithm and a fuzzy model to estimate the quality of the sugarcane crop and the probability of the presence of pests and diseases through the prediction of uncertain variables. Wind speed, cloudiness, humidity, and thermal amplitude were considered variables of interest because parameters out of control of these variables generate a state of thermal stress, triggering pests and diseases that reduce crop quality and sugar production. This research uses geospatial information to simplify the exchange of information through a detection algorithm using real-time satellite images and a fuzzy model to estimate crop quality and prevent climate change-related problems. The variables humidity and cloudiness determine sugarcane quality as they are related to crop phenology and the probability that the crop will develop pests and diseases. In contrast, the intelligent system showed a correlation of over 93% for predicting the variables of interest.

Nutrient leaching potential along a time series of forest water reclamation facilities in northern Idaho

Forest water reclamation is a decades-old practice of repurposing municipal reclaimed water using land application on forests to filter nutrients and increase wood production. However, long-term application may lead to nutrient saturation, leaching, and potential impairment of ground and surface water quality. We studied long-term effects of reclaimed water application on nutrient leaching potential in a four-decade time series of forest water reclamation facilities in northern Idaho. Our approach compared reclaimed water treated plots with untreated control plots at each of the forest water reclamation facilities. We measured soil nitrifier abundance and net nitrification rates and used tension lysimeters to sample soil matrix water and drain gauges to sample from a combination of matrix and preferential flow paths. We determined nutrient leaching as the product of soil water nutrient concentrations and model-estimated drainage flux. There was more than 450-fold increase in nitrifier abundance and a 1000-fold increase in net nitrification rates in treated plots compared with control plots at long-established facilities, indicating greater nitrate production with increased cumulative inputs. There were no differences in soil water ammonium, phosphate, and dissolved organic nitrogen concentrations between control and effluent treatments in tension lysimeter samples. However, concurrent with increased nitrifier abundance and net nitrification, nitrate concentration below the rooting zone was 2 to 4-fold higher and nitrate leaching was 4 to 10-fold higher in effluent treated plots, particularly at facilities that have been in operation for over two decades. Thus, net nitrification and nitrifier abundance assays are likely indicators of nitrate leaching potential. Inorganic nutrient concentrations in drain gauge samples were 2 to 11-fold higher than lysimeter samples, suggesting nutrient losses occurred predominantly through preferential flow paths. Nitrate was vulnerable to leaching during the wet season under saturated flow conditions. Although nitrogen saturation is a concern that should be mitigated at long-established facilities, these forest water reclamation facilities were able to maintain average soil water nitrate concentrations to less than 2 mg L−1, so that nitrogen and phosphorous are effectively filtered to below safe water standards.

The response of non-point source pollution to climate change in an orchard-dominant coastal watershed

China is the largest global orchard distribution area, where high fertilization rates, complex terrain, and uncertainties associated with future climate change present challenges in managing non-point source pollution (NPSP) in orchard-dominant growing areas (ODGA). Given the complex processes of climate, hydrology, and soil nutrient loss, this study utilized an enhanced Soil and Water Assessment Tool model (SWAT-CO2) to investigate the impact of future climate on NPSP in ODGA in a coastal basin of North China. Our investigation focused on climate-induced variations in hydrology, nitrogen (N), and phosphorus (P) losses in soil, considering three Coupled Model Intercomparison Project phase 6 (CMIP6) climate scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Research results indicated that continuous changes in CO2 levels significantly influenced evapotranspiration (ET) and water yield in ODGA. Influenced by sandy soils, nitrate leaching through percolation was the principal pathway for N loss in the ODGA. Surface runoff was identified as the primary pathway for P loss. Compared to the reference period (1971–2000), under three future climate scenarios, the increase in precipitation of ODGA ranged from 15% to 28%, while the growth rates of P loss and surface runoff were the most significant, both exceeding 120%. Orchards in the northwest basin proved susceptible to nitrate leaching, while others were more sensitive to N and P losses via surface runoff. Implementing targeted strategies, such as augmenting organic fertilizer usage and constructing terraced fields, based on ODGA's response characteristics to future climate, could effectively improve the basin's environment.

Soil Nutrient Inflow-Outflow Dynamics and Balance on Agricultural Cultivated Farms in Northern Ethiopia

Soil fertility is the controlling factor of agricultural production worldwide including Waghimera zone, Ethiopia. However, it has been diminished from time to time and leads to low crop yield. Measuring of soil nutrient inflow-outflow affords necessary information about the current nutrient status of the soils, and to take appropriate nutrient management practices. The study was conducted to estimate the full soil nutrient balance of cultivated farms in the northern, of Ethiopia, in the 2020/21 main season. Inflow and Outflow of N, P, and K into, and out of farms were measured through the interview, field measurement, laboratory analysis, USLE model, and pedo-transfer functions. The full N balance of barley, tef, and wheat were -66.7, -8.9, and -47.1 kg ha-1 yr-1, respectively. P full balance was -5.4, 1.4, and -1.9 kg ha-1 yr-1 for barley, tef, and wheat farms, respectively. Whereas, K balance was also -12.4, -3.3, and -6 kg ha-1 yr-1 for barley, tef, a nd wheat, respectively. The balance quantification was done by subtracting nutrient outflows from the inflows. The results revealed that N, P, and K had negative balances except for P in tef. Grain yield and crop residue removal were the major paths of nutrient loss. To sustain, and boost agricultural production, reversing the imbalance between inflows, and outflows is critically essential for the study area. The current highly depleted nutrient should be corrected by adding sufficient organic, and inorganic nutrient sources, like in situ manuring, biochar, green manure, and remaining crop residue in the fields.

The efficiency of different mulch types and dose applications on runoff, soil, and nutrient losses under simulated rainfall

AbstractMulching is one of the best management practices used in soil and water conservation studies. The aim of this study is to determine the effects of different mulch types and doses on runoff coefficient (Rc), soil loss (Er), sediment concentration (Sc), time to ponding (tp), runoff generation time (tr), percolated (pw) and retained (rw) water and total losses of nitrate‐nitrogen (NO3−), ammonium‐nitrogen (NH4+), total nitrogen (TN), phosphate‐phosphorus (PO43−), and total organic carbon (TOC) under simulated rainfall in the laboratory. Three different mulch materials (dry weed, peanut hay, and wheat straw) were applied at four different doses (0, 2, 4, and 6 t/ha) on the experimental plots. A simulated rainfall intensity of 97 mm/s was applied for an hour. All mulch types and doses reduced Rc, and the most effective reduction was found in 2 t/ha dry weed mulch applied plots. The most effective application for reducing soil loss was 6 t/ha peanut hay mulch. The most effective application for delaying the ponding time and runoff generation time was the 4 t/ha application of wheat straw mulch. The highest pw and rw were found in 6 t/ha and 4 t/ha doses of dry weed mulch applications, respectively. The most effective application for reducing NH4+ losses was found in 4 t/ha wheat straw application plots. The most effective mulch type and dose for reducing NO3− loss was 6 t/ha of dry weed mulch. The lowest TN loss was found in the plots where 6 t/ha of peanut hay mulch was applied. In terms of PO43− losses, the lowest loss was in 6 t/ha of dry weed mulch plots. The lowest TOC loss was at 4 t/ha of straw mulch applications. Mulching can be a good natural‐based solution for reducing soil, water, and nutrient loss. However, different mulch types and doses should be tested for different environmental conditions to determine the most cost‐effective mulch type and dose.

How to Achieve a 50% Reduction in Nutrient Losses From Agricultural Catchments Under Different Climate Trajectories?

AbstractUnder persistent eutrophication of European water bodies and a changing climate, there is an increasing need to evaluate best‐management practices for reducing nutrient losses from agricultural catchments. In this study, we set up a daily discharge and water quality model in Hydrological Predictions of the Environment for two agricultural catchments representative for common cropping systems in Europe's humid continental regions to forecast the impacts of future climate trajectories on nutrient loads. The model predicted a slight increase in inorganic nitrogen (IN) and total phosphorus (TP) loads under RCP2.6, likely due to precipitation‐driven mobilization. Under RCP4.5 and RCP8.5, the IN loads were forecasted to decrease from 16% to 26% and 21%–50% respectively, most likely due to temperature‐driven increases in crop uptake and evapotranspiration. No distinct trends in TP loads were observed. A 50% decrease in nutrient loads, as targeted by the European Green Deal, was backcasted using a combination of management scenarios, including (a) a 20% reduction in mineral fertilizer application, (b) introducing cover crops (CC), and (c) stream mitigation (SM) by introducing floodplains. Target TP load reductions could only be achieved by SM, which likely results from secondary mobilization of sources within agricultural streams during high discharge events. Target IN load reductions were backcasted with a combination of SM, fertilizer reduction, and CC, wherein the required measures depended strongly on the climatic trajectory. Overall, this study successfully demonstrated a modeling approach for evaluating best‐management practices under diverging climate change trajectories, tailored to the catchment characteristics and specific nutrient reduction targets.

Optimizing the drying process with the surface response method for snap beans, sweet corn, and carrots

Abstract Vegetables contain many nutrients that are susceptible to loss when dried. Pre-treatment is needed to reduce nutrient loss during drying. This research aims to determine optimal pre-treatment and drying conditions for dried vegetables. Optimization using the D-optimal response surface method for snap beans, carrots, and sweet corn. The optimized process conditions are drying temperature (45°C, 50°C, 55°C); blanching technique at 75°C (immersion, steaming); freezing treatment (with freezing -20°C 24 hours, without freezing); and type of dryer (cabinet dryer, dehydrator). The research results show that immersion blanching (75°C), freezing (-20°C, 24 hours), and cabinet dryer type at 50°C are the best conditions for processing dried snap beans. The best method for drying sweet corn is immersion blanching (75°C), freezing (-20°C, 24 hours), and drying in a dehydrator-type drying at 50°C. Immersion blanching (75°C), freezing (-20°C, 24 hours), and dehydrator-type dryer at 55°C are the best methods for drying carrots.

Missing carcasses, lost nutrients: Quantifying nutrient losses from deer culling practices in Scotland

Abstract Deer management has become an integral part of ecosystem recovery efforts across the globe. Within Scotland, annual deer culls have been implemented to control deer browsing, with the carcasses most often removed from the landscape. Given that animal bodies concentrate large quantities of nutrients, this practice may deplete ecosystems of vital nutrients. We quantified the nitrogen, phosphorous and calcium losses from the removal of culled deer carcasses using nationwide statutory cull reports for four deer species in Scotland between 2010 and 2021. We estimate that annual losses from carcass removal over this period averaged 195,652 kg of nitrogen, 152,834 kg of phosphorus and 251,188 kg of calcium across Scotland. While both red and roe deer were culled at a much higher rate than the other two species red deer culls accounted for approximately 70% of the nutrients lost. Further, while large quantities of all three nutrients were removed from the landscape, calcium losses were particularly high. We then calculated nutrient losses within the three land classifications used in statutory cull reporting—agricultural areas, open range and woodlands—across Scotland's Deer Count Areas. Using data from the literature, we considered these losses in the context of other major environmental inputs and outputs within each land classification. Our results demonstrate that while open range lost more nutrients compared to the other two land classifications, culling resulted in high rates of phosphorus and calcium loss throughout all land classifications when compared to other environmental inputs. Practical implication. Our findings suggest that current practices of carcass removal are gradually stripping nutrients from the Scottish landscape, potentially undermining habitat recovery goals. While this study offers a preliminary, coarse scale summary of the issue, the way forward requires further study of local effects from carcass removal on nutrient pools and balancing deer management with habitat function through interwoven deer and nutrient management strategies.

Effect of Gastrodia elata Bl Cultivation under Forest Stands on Runoff, Erosion, and Nutrient Loss

(1) Background: The understory planting of Chinese herbal medicine is a common soil and water conservation farming measure, and this approach makes full use of the natural conditions of the understory. However, a large number of studies on soil erosion have focused on the simulation of natural indoor conditions, and there are very few investigations on soil erosion caused by understory planting in the field. This study aims to investigate the effects of different slopes on soil and water and nitrogen–phosphorus nutrient loss from understory planting of Gastrodia elata Bl by changing the vegetation structure and soil structure of forest land. (2) Methods: To reveal the nitrogen and phosphorus loss and flow and sediment characteristics of the understory planting of Gastrodia elata Bl, runoff plots were set up in a field, and three surface slopes (5°, 15°, and 20°) were designed to collect runoff sediments and compare the soil and water loss between the natural slopes and those with Gastrodia elata Bl. This provides a basis for the restoration of vegetation cover and the enhancement of soil fertility. (3) Results: The total loss of soil, water, nitrogen, and phosphorus in the forested land with Gastrodia elata Bl increased significantly compared with that in the natural forested land, and the greater the slope was, the greater the loss was. (4) Conclusions: Planting Gastrodia elata Bl should be avoided in areas with steep slopes and serious soil erosion. However, some soil and water conservation engineering measures can be taken, such as the construction of retaining walls, drainage ditches, etc., to minimize the scouring and erosion of soil by rainwater.

Watershed-Based Participatory Sustainable Land Management using Integrated physical SWC Measure in Ilasa Watershed of Goba District, Bale Highland South-Eastern Ethiopia

Soil erosion is among the most challenging and continuous environmental problems in the highlands of Bale particularly in Ilasa Watershed of Goba District. Soil erosion which emanates from both anthropogenic and natural causes currently results decline in agricultural productivity, crop production on the other hand increases downstream flooding and reservoir sedimentation, and loss of valuable plant nutrients. Soil and water conservation (SWC) practices have been carried out to solve land degradation and erosion severity problems in the Ilasa Watershed through participatory approaches the objective of this study was to implement integrated physical SWC practices through participatory approach in the Ilasa watersheds; to rehabilitate degraded watershed using different physical SWC measures and to minimize the risk of soil erosion and increasing soil depth by trapping sediment loss from Ilasa watershed. Hence, different participatory integrated watershed management practices were introduced in the Ilasa watershed for five consecutive years to avert the problem of soil erosion. Community participatory in integrated watershed management particularly soil and water conservation measures interventions for degraded rehabilitation and gulley treatment were capacitated through training, practical field works, and researchable materials support. Awareness creation, increasing knowledge and skill of farmers, providing technical and resource supports, and implementing slope based appropriate SWC structure could help sustainable land management that ensures environmental quality and food security in the study area as well as in the other areas having related biophysical and socioeconomic settings. Among the major types of physical SWC structures and gulley rehabilitation structures constructed in the study watershed were soil bund; stone bund; stone-faced soil bund and cut-off drains, gully reshaping and filling, brushwood check dam, loose stone check dame, sandbag check dam ...

Effect of blanching conditions and solar drying on selected nutritional, anti-nutritional and bioactive components of formulated avocado seed powder

Avocado (Persea americana Mill) seeds are mainly considered as waste by-products of avocado fruit processing in many countries, including Tanzania despite their potential health and economic benefits. The present work investigated the effect of hot water blanching and solar drying treatments on nutritional, bioactive, and cyanogenic glycosides of avocado seed samples in an attempt to develop quality avocado seed powders (ASPs) by using solar drying technology. Results showed that total ash, crude protein, crude fiber, total phenolic, proanthocyanidins, and cyanogenic glycosides contents showed a significant reduction in avocado seed powders with respect to increased blanching temperature and time. On the other hand, crude fat and total carotenoids contents, showed a decline with respect to increased temperature only. Blanching treatment at 85 °C for 10 minutes retained a significant amount of total ash (86.9%), crude fat (100%), crude protein (78.8%), crude fiber (91.6%), total carotenoids (43.6%) and total phenol contents (47.0%) in developed avocado seed powder. Cyanogenic glycosides were highly reduced at 95 °C for 20 minutes (81.1%) than at 85 °C for 10 minutes (58.5%). However, the level of cyanogenic glycosides in all avocado seed powders are far below the lethal dose (36 mg/100 g) of hydrocyanic acid. The significant high losses of nutrients and phytochemicals was observed at a blanching treatment of 95 °C for 20 minutes. This could be due to prolonged leaching of soluble compounds to hot water and degradation of heat-sensitive bioactive compounds. The aforementioned results revealed that, different temperatures and times during hot water blanching significantly influence the quality of formulated avocado seed powder. Therefore, hot water blanching treatment at 85 °C for 10 minutes and solar drying technology could be employed to produce a nutrient-rich and palatable avocado seed powder that can find its use in normal food consumption and food processing industries, particularly in low income settings. Key words: Avocado seed, avocado seed powder, solar drying, hot water blanching, utilization

Optimizing Tomato Cultivation: Impact of Ammonium–Nitrate Ratios on Growth, Nutrient Uptake, and Fertilizer Utilization

Tomatoes, an essential crop in controlled environments, benefit significantly from the careful use of nitrogen fertilizers, which are crucial for improving both yield and nitrogen efficiency. Using a tomato pot experiment arranged in a facility greenhouse, five treatments were established as follows: a control excluding the application of nitrogen fertilizer (C), and applications of ammonium nitrogen and nitrate nitrogen with nitrogen mass ratios of 0:100 (A0N100), 25:75 (A25N75), 50:50 (A50N50), 75:25 (A75N25), and 100:0 (A100N0), to study the effects of different ratios of nitrogen mass on tomato yield, quality, nutrient accumulation, and nitrogen fertilizer utilization. The results showed that compared with C, the different ammonium–nitrate ratios significantly increased the yield, dry matter mass, N, P, and K accumulation, soluble solids, soluble sugars, and vitamin C content (Vc) of the tomatoes. Among all the treatments, A75N25 tomatoes had the highest dry matter accumulation, nitrogen, phosphorus, and potassium accumulation in fruits, soluble sugar, and soluble solids content. The differences in tomato yield and nitrogen fertilizer utilization between A75N25 and A100N0 were insignificant but their values were significantly higher than those of the other treatments. A75N25 had the highest nitrogen fertilizer utilization rate, 42.1% to 82.3% higher than C, A25N75, and A50N50. Hence, an ammonium-to-nitrate nitrogen mass ratio of 75:25 optimized tomato yield and quality in a controlled environment while minimizing nutrient loss.

Severity of topsoil compaction controls the impact of skid trails on soil ecological processes

Abstract Skid trails are a major management‐induced disturbance in temperate forest ecosystems with considerable impact on soil ecological processes that are so far poorly understood. In German forests, skid trails comprise 10%–20% of the forest area that is potentially affected by soil compaction through heavy machinery. We systematically investigated the influence of skid trails on physical, chemical and microbiological soil parameters at 84 paired plots across four Central European forest types. In low mountain forests with steeper topography, skid trails had more drastic effects than in lowland forests. Skid trails in low mountain areas showed a decrease in the C to N ratio of microbial biomass (MBC/MBN), as well as increased microbial (MBC/SOC) and enzyme activities leading to faster carbon turnover (lower C/N, EOC/EN) and increased CO2 losses (CO2/SOC) from the soil. The overall effects of the skid trails in lowland forests were small. On base‐poor soils, we found an increase in the MBC/MBN ratio, while skid trails in base‐rich lowland soils showed a reduction in CO2/SOC, suggesting a proportional increase in soil carbon storage. Regardless of region‐specific effects, the relative increase in the bulk density of the fine soil was identified as a ‘golden trait’ that determined the effects of skid trails on many soil parameters, as shown by negative correlations with SOC, N, MBC, MBN, MBP, MBC/SOC and CO2/SOC and positive ones with the activities of certain hydrolytic enzymes. Synthesis and applications: Our data clearly showed that carbon conversion processes and soil respiration leading to significant carbon and nutrient losses increased significantly on skid trails in low mountain regions with relatively steep slopes, which was in sharp contrast to lowland sites. The strong context dependence of our findings suggests that the mapping of soil conditions in terms of slope, substrate and moisture with high spatial resolution is mandatory to assess the vulnerability of sites to soil compaction by heavy machinery. Based on such vulnerability analysis, negative impacts can be minimised through the designation of permanently fixed skid trails, technical adaptation of vehicles (e.g. wide base tyres) as well as careful planning and timing of management operations that should be restricted to dry weather and soil moisture conditions or periods of frost.

A method to derive nitrogen transport factors for New Zealand's agricultural lands

Risk index tools have the potential to assist farmers in making strategic decisions regarding their farm design to manage losses of nutrients. Such tools require a vulnerability framework, and these are often based on scores or rankings. These frameworks struggle to take account of interactions between elements of the physical environment. Process-based simulation models inherently take account of interactions and may be a viable alternative to score-based methods. We describe the method to populate a database of transport factors that covers the agricultural lands of New Zealand that is designed for usage as the susceptibility framework within a risk index tool. The method gives both leaching and runoff transport factors and gives values by month. The simulation model used had already been validated for simulating water and nitrogen balances and the generated spatial patterns of the transport factors was validated via expert assessment. These features allow good representation of the risks posed across a wide range of farming activities.•Use of a simulation model to quantify transport factors.•Captures the interactions between soil and weather factors in the physical environment.•Produces a country-wide database intended as a susceptibility framework for a risk index tool.