Lysimeter Study Research Articles

Biochar benefits carbon off-setting in blue-green infrastructure soils - A lysimeter study

Carbon sequestration with amendments in blue-green infrastructure soils could off-set anthropogenic greenhouse gas emissions to alleviate climate change. In this 3-year study, the effects of wheat straw and its biochar on carbon sequestration in an urban landscaping soil were investigated under realistic outdoor conditions using two large-scale lysimeters. Both amendments were carried out by incorporating pellets at 0–15 cm soil depth with an equivalent initial total carbon input of 2% of the dry soil weight. Soil carbon, carbon isotope ratios, dissolved carbon in leachates, CO2–C emissions, carbon fixed in above ground vegetation, soil water content, soil bulk electrical conductivity, and water infiltration rates, were then compared between the 2 lysimeters. After 3 years, we observed that, despite having a 17.2% lower vegetation growth, soil organic and inorganic carbon content was higher by 28.8% and 41.5%, respectively, in biochar as compared to wheat straw amended soil. Carbon isotope analysis confirmed the greater stability of the added carbon in the biochar amended soil. Water content was on average 23.2% and 13.0% in the straw pellet and biochar amended soil, respectively, whereas water infiltration rates were not significantly different between the two lysimeters. Overall, the incorporation of wheat straw biochar into soil could store an estimated 30 tonnes of carbon per hectare in city blue-green infrastructure spaces. Interviews involving institution stakeholders examined the feasibility of this biochar application. Stakeholders recognized the potential of biochar as an environment-friendly means for carbon offsetting, but were concerned about the practicality of biochar production and application into soil and increased maintenance work. Consequently, additional potential benefits of biochar for environmental management such as improving the quality of polluted run-off in stormwater treatment systems should be emphasized to make biochar an attractive proposition in sustainable urban development.

Evaluation of the Transformation and Leaching Behavior of Two Polyfluoroalkyl Phosphate Diesters in a Field Lysimeter Study.

In this study, 6:2 and 8:2 polyfluoroalkyl phosphate diester (diPAP) were individually investigated in lysimeters under near-natural conditions. Leachate was sampled for 2 years, as was the soil after the experiment. In the leachate of the diPAP-spiked soils, perfluorocarboxylic acids (PFCAs) of different chain lengths were detected [23.2% (6:2 diPAP variant) and 20.8% (8:2 diPAP variant) of the initially applied molar amount]. After 2 years, the soils still contained 36-37% 6:2 diPAP and 41-45% 8:2 diPAP, respectively, in addition to smaller amounts of PFCAs (1.5 and 10.6%, respectively). Amounts of PFCAs found in the grass were low (<0.1% in both variants). The recovery rate of both 6:2 diPAP and 8:2 diPAP did not reach 100% (63.9 and 83.2%, respectively). The transformation of immobile diPAPs into persistent mobile PFCAs and their transport into the groundwater shows a pathway for human exposure to hazardous PFCAs through drinking water and irrigation of crops.

Effects of winter pulsed warming and snowmelt on soil nitrogen cycling in agricultural soils: A lysimeter study

In cold regions, climate change is expected to result in warmer winter temperatures and increased temperature variability. Coupled with changing precipitation regimes, these changes can decrease soil insulation by reducing snow cover, exposing soils to colder temperatures and more frequent and extensive soil freezing and thawing. Freeze-thaw events can exert an important control over winter soil processes and the cycling of nitrogen (N), with consequences for soil health, nitrous oxide (N2O) emissions, and nearby water quality. These impacts are especially important for agricultural soils and practices in cold regions. We conducted a lysimeter experiment to assess the effects of winter pulsed warming, soil texture, and snow cover on N cycling in agricultural soils. We monitored the subsurface soil temperature, moisture, and porewater geochemistry together with air temperature, precipitation, and N2O fluxes in four agricultural field-controlled lysimeter systems (surface area of 1 m2 and depth of 1.5 m) at the University of Guelph’s Elora Research Station over one winter (December 2020 to April 2021). The lysimeters featured two soil types (loamy sand and silt loam) which were managed under a corn-soybean-wheat rotation with cover crops. Additionally, ceramic infrared heaters located above two of the lysimeters were turned on after each snowfall event to melt the snow and then turned off to mimic snow-free winter conditions with increased soil freezing. Porewater samples collected from five depths in the lysimeters were analyzed for total dissolved nitrogen (TDN), nitrate (NO3−), nitrite (NO2−), and ammonium (NH4+). N2O fluxes were measured using automated soil gas chambers installed on each lysimeter. The results from the snow removed lysimeters were compared to those of lysimeters without heaters (with snow). As expected, the removal of the insulating snow cover resulted in more intense soil freeze-thaw events, causing increased dissolved N loss from the lysimeter systems as N2O (from the silt loam system) and via NO3− leaching (from the loamy sand system). In the silt loam lysimeter, we attribute the freeze thaw-enhanced N2O fluxes to de novo processes rather than gas build up and release. In the loamy sand lysimeter, we attribute the increased NO3− leaching to the larger pore size and therefore lower water retention capacity of this soil type. Overall, our study illustrates the important role of winter snow cover dynamics and soil freezing in modulating the coupled responses of soil moisture, temperature, and N cycling.

The role of soil texture on diurnal and seasonal cycles of potential evaporation over saturated bare soils – Lysimeter studies

• Diurnal and seasonal cycles of PE rate over three different saturated soil textures were assessed using a unique lysimeter. • The textures showed different PE sums, with the largest differences during daytime in spring and summer. • PE differences over textures were reproduced well by the energy balance method. • Simplifying the estimate of ground heat flux results in large deviations from measured PE. Calculating actual bare soil evaporation (E a ) based on potential evaporation (PE) is a widely followed approach in many disciplines such as hydrogeology, hydrology and agricultural sciences. The influence of soil texture on PE is rarely considered in these approaches. In this work, seasonal and diurnal cycles of PE over saturated bare soils were assessed using a unique lysimeter experiment in the Guanzhong Basin, China. The assessment was made for three different soil textures including fine sand (PE fine ), coarse sand (PE coarse ) and gravel (PE gravel ). Meteorological variables, soil heat flux and soil temperatures were measured at a high temporal resolution for more than 14 consecutive months. Potential evaporation rates over saturated bare soil showed clear differences between fine sand, coarse sand and gravel on an annual basis. PE fine was higher than PE coarse and PE gravel (7.3 % and 11.0 % respectively). The differences between measured PE rates over different surfaces were especially pronounced during daytime in spring and summer, but showed minor differences in autumn and winter. These results are quantitatively explained with detailed calculations of the surface energy balance and it is found that differences in available energy over the soil textures, related to different albedos, as well as different porosities and thermal properties for the materials (which influence soil temperatures) explain the differences. This shows that PE is different for different soil textures, which is neglected in most hydrological studies. Nevertheless, the full-form Penman-Monteith equation can reproduce the PE differences over soil textures quite well in autumn and winter, but a simplified approach to calculate the ground heat flux does not allow to reproduce PE differences between textures.

In situ lysimeter experiment of leaching pollutants from municipal waste with physicochemical status and microbiome condition

• Effluents have a specific electrical conductivity similar to landfill leachates. • The microbiological activity in the tested leachate samples shows seasonality. • Temperatures in summer reduced the ability of the microbiome to oxidize polymers. Lysimeter tests are an ideal supplement to monitoring tests performed in the area of landfills. This article presents an interdisciplinary lysimeter experiment that used hydrogeological, biochemical, and microbiological studies to evaluate the process of leaching pollutants from waste. The obtained results of leachate tests indicate that the EC value was as high as 31 mS/cm which corresponds to poor water quality. Additionally, high concentrations of chlorides (up to 5095 mg/L) and sulphates (up to 10107 mg/L) were observed. The results of microbiological tests confirm the seasonality. The statistically significant (p < 0.05) difference in the number of heterotrophic bacteria was denoted between autumn (1.6·107 CFU cm-3) and winter (1.5·105 CFU cm-3.The analysis of the ability to utilize nitrogen and phosphorus sources showed seasonal differences in the use of substrates containing these biogenic elements. It was observed that nitrogen-containing compounds were most intensively used in winter and the least in spring while phosphorus compounds were the most intensively oxidized in summer. Presented results confirm that lysimeter studies can play a valuable role in the construction of landfills for the best method of waste isolation and limiting the growth of microorganisms.

Nitrate Leaching Mitigation Options in Two Dairy Pastoral Soils and Climatic Conditions in New Zealand.

This lysimeter study investigated the effect of late-autumn application of dicyandiamide (DCD), co-poly acrylic-maleic acid (PA-MA), calcium lignosulphonate (LS), a split-application of calcium lignosulphonate (2LS), and a combination of gibberellic acid (GA) and LS (GA + LS) to reduce N leaching losses during May 2020 to December 2020 in lysimeter field sites in Manawatu (Orthic Pumice soil) and Canterbury (Pallic Orthic Brown soil), New Zealand. In a second application, urine-only, GA only and GA + LS treatments were applied during July 2020 in mid-winter on both sites. Results showed that late-autumn application of DCD, 2LS and GA + LS reduced mineral N leaching by 8%, 16%, and 35% in the Manawatu site and by 34%, 11%, and 35% in the Canterbury site, respectively when compared to urine-only. There was no significant increase in cumulative herbage N uptake and yield between urine-treated lysimeters in both sites. Mid-winter application of GA and GA + LS reduced mineral N leaching by 23% and 20%, respectively in the Manawatu site relative to urine-only treated lysimeters, but no significant reduction was observed in the Canterbury site. Our results demonstrated the potential application of these treatments in different soils under different climate and management conditions.

Effect of Alternate Wetting and Drying Irrigation Practice on Rice Crop Growth and Yield: A Lysimeter Study

Effect of Alternate Wetting and Drying Irrigation Practice on Rice Crop Growth and Yield: A Lysimeter Study

Trend Analyses of Percolation of Atmospheric Precipitation Due to Climate Change: Case Study in Lithuania

The aim of this paper is to identify the trends of changes in atmospheric precipitation percolation under the changing climate conditions of Lithuania (the East Baltic region) based on long-term lysimeter studies. Data from 1987–2022 research (n = 1296) was used to determine trends in precipitation infiltration changes. Two 10-year periods, 1989–1998 and 2011–2020, were selected from the whole observation period (1987–2022) to assess changes in precipitation infiltration due to climate change. The air temperature has increased significantly in November (+3.4 °C) and December (+3.3 °C), with a +2.2 °C increase in the standard climate normal. The distribution of yearly precipitation has changed, with the annual amount decreasing from 686 to 652 mm. Precipitation increased the most in July and August (10.9 and 22.9 mm). In autumn, the amount of precipitation decreased by 7.9–31.1 mm. The number of rainy days did not change during the year, but the frequency of heavy precipitation increased significantly in August. The annual percolation increased by 14.2% over 2011–2020 compared to 1989–1998. Percolation increased by 19.0, 22.3, and 20.1% during the spring, autumn, and winter, respectively, and decreased by 35.0% in summer. The increase in annual percolation is mostly related to the increase in temperature during the cold season: November and December. During these months, the likelihood of early freeze formation, which interrupts gravitational water percolation in soil, is significantly reduced. In the spring, the increase in average air temperatures in March leads to faster melting of the winter snow in a shorter period, which significantly increases percolation processes. In Lithuania, higher percolation in autumn and winter, when part of the agricultural land is not covered by vegetation, may lead to higher leaching of chemical elements.

Examination of the Effectiveness of Controlled Release Fertilizer to Balance Sugarcane Yield and Reduce Nitrate Leaching to Groundwater

Groundwater pollution by nitrate leaching from sugarcane fields in Okinawa is recognized as a critical issue. Controlled release fertilizer (CRF) has the potential to reduce N leaching from cropping systems. The study focused on confirming the effectiveness of CRF at balancing sugarcane yield and reducing nitrate leaching from sugarcane fields via a water footprint (WF) approach. A lysimeter study was conducted using four treatments: (i) bare land, (ii) P and K fertilization without N, (iii) urea fertilization, and (iv) CRF application. According to the results, for both plant cane and ratoon, the total sugarcane dry weight obtained for CRF was higher compared to urea application. The cumulative nitrate-N leaching of the plant cane season for all treatments was higher than of the ratoon season. For the total crop cycle (plant cane plus ratoon), heavier nitrate-N leaching was observed in the urea-applied condition than in the CRF-applied condition. For both crop seasons, the total sugarcane WF of the CRF application (plant cane: 192.33 m3/t, ratoon: 190.47 m3/t) was lower than that of the urea application (plant cane: 233.47 m3/t, ratoon: 237.59 m3/t). WF values indicated that the CRF application had a lower impact on the groundwater of the area.

Ecotoxicity and fate of silver nanomaterial in an outdoor lysimeter study after twofold application by sewage sludge

The increasing use of antibacterial silver nanomaterials (AgNM) in consumer products leads to their release into sewers. High amounts of AgNM become retained in sewage sludge, which causes their accumulation in agricultural soils when sewage sludge is applied as fertilizer. This increase in AgNM arouses concerns about toxicity to soil organisms and transfer within trophic levels. Long-term field studies simulating the sewage sludge pathway to soils are sparse, and the effects of a second sewage sludge application are unknown. In this perennial field lysimeter study, a twofold application of AgNM (NM-300K, 2 + 3 mg AgNM/kg dry matter soil (DMS)) and a onefold application of silver nitrate (AgNO3, 2 mg Ag/kg DMS) by sewage sludge to the uppermost 20 cm of the soil (Cambisol) were applied. The response of microorganisms to the applications was determined by measuring the inhibition of ammonium-oxidizing bacteria (AOB). Silver concentration in soil, leachates, and crops were measured after acid digestion by inductively coupled plasma mass spectrometry (ICP-MS). Almost no vertical Ag translocation to deeper soil layers and negligible Ag release to leachates suggest that soil is a large sink for AgNM and AgNO3. For AgNM, an increase in toxicity to AOB was shown after the second sewage sludge application. The application of AgNO3 resulted in long-term toxicity comparable to the toxicity of AgNM. Low root uptake from both AgNM- and AgNO3-spiked lysimeters to crops indicates their incomplete immobilization, which is why food chain uptake cannot completely be excluded. However, the root-shoot barrier for wheat (9.8 → 0.1 mg/kg) and skin body barrier for sugar beets (1.0 → 0.2 mg/kg) will further reduce the accumulation within trophic levels. Moreover, the applied AgNM concentration was above the predicted environmental concentration, which is why the root uptake might be negligible in agricultural practice.

Aus rice root architecture variation contributing to grain yield under drought suggests a key role of nodal root diameter class.

The aus rice variety group originated in stress-prone regions and is a promising source for the development of new stress-tolerant rice cultivars. In this study, an aus panel (~220 genotypes) was evaluated in field trials under well-watered and drought conditions and in the greenhouse (basket, herbicideand lysimeter studies) to investigate relationships between grain yield and root architecture, and to identify component root traits behind the composite trait of deep root growth. In the field trials, high and stable grain yield was positively related to high and stable deep root growth (r = 0.16), which may indicate response to within-season soil moisture fluctuations (i.e., plasticity). When dissecting component traits related to deep root growth (including angle, elongationand branching), the number of nodal roots classified as 'large-diameter' was positively related to deep root growth (r = 0.24), and showed the highest number of colocated genome-wide association study (GWAS) peaks with grain yield under drought. The role of large-diameter nodal roots in deep root growth may be related to their branching potential. Two candidate loci that colocated for yield and root traits were identified that showed distinct haplotype distributions between contrasting yield/stability groups and could be good candidates to contribute to rice improvement.

Sulfur fertilization strategy affects grass yield, nitrogen uptake, and nitrate leaching: A field lysimeter study#

AbstractBackgroundGlobally and at the European Union level there are mounting concerns regarding nitrogen (N) losses from agricultural systems and pressure to reduce N losses to water and air. Suboptimal plant sulfur (S) availability can reduce plant N efficiency and thereby increase N loss potential. Climate change action demands lower sulfur dioxide emissions thus S deposition levels are at an all‐time low.AimsThe objectives of the current study were to (1) determine the potential for adequate S nutrition to increase grassland yield and N efficiency, (2) determine if alleviating S deficiency reduces nitrate leaching, and (3) evaluate a number of strategies for applying S including the use of cattle slurry.MethodsThis work was completed using a free‐draining sandy loam grassland lysimeter facility. There were six treatments using calcium ammonium nitrate (CAN), CAN + calcium sulfate (CAN+S), ammonium sulfate + CAN (AS+CAN), and slurry (Slurry+CAN and Slurry+CAN+S, respectively) to deliver S strategies. The yield, plant N and S uptake, and nitrate and sulfate leachate were measured to compare treatments.ResultsApplication of mineral S fertilizer increased yields significantly (up to 2,907 kg ha–1) and increased apparent fertilizer nitrogen recovery from 39% to 47–49%. Alleviating S deficiency also significantly decreased nitrate leaching to levels not differing significantly from the control. There was a reduction of 46% in nitrate leaching with the addition of mineral S (CAN+S and AS+CAN) compared to N only. The nitrate concentration standard for drinking water was not breached for treatments that included S (6.6–11 mg NO3–‐N L–1), whereas it was breached for those without S (23–40 mg NO3–‐N L–1). The S applied in the slurry treatment was not adequate (9 kg S ha–1) to meet plant requirements.ConclusionThis study provides evidence that optimization of S nutrition has the potential to deliver large agronomic and environmental benefits along with potential as a nitrate leaching migration strategy on S‐deficient soils.

Municipal sewage sludge as a source of microelements in sustainable plant production: a laboratory lysimeter study

The aim of the work was to characterize the samples of sewage sludge (SSL) originated from the Wastewater Treatment Plant Piešťany (TAVOS, a.s., Trnava, Slovakia) in terms of their potential application into the soils. Within the physico-chemical characterization of SSL, the samples were analysed in terms of the values of pH, cation exchange capacity (CEC), total organic carbon (TOC), water holding capacity (WHC), as well as the presence of heavy metals. It was found that SSL contained significant amounts of microelements Zn (1,269 mg.kg-1, d.w.) and Cu (224 mg.kg-1, d.w.). Laboratory lysimeter experiments involving the application of SSL into the top layer of agriculturally used soil (0 – 10 cm) forming a soil column, in which seedlings of tobacco (Nicotiana tabacum L.) were cultivated, showed that in the case of SSL application in the highest permitted amounts (15 t.ha-1) only 0.11 % Zn and 0.07 % Cu were released into the soil eluate during a 28 day of exposure, while in tobacco plants 0.13 % Zn and 0.05 % Cu were accumulated from the total amount of Zn and Cu originated from the application of SSL (Zn – 133 mg and Cu – 23.5 mg). When applying SSL in amount 30 t.ha-1 i.e., in the dose exceeding the permitted limits, only 0.02 % Zn and 0.04 % Cu were released into the soil eluate and 0.16 % Zn and 0.09 % Cu were accumulated in tobacco plants from the applied amount of SSL (Zn – 267 mg and Cu – 47.0 mg).

A lysimeter study on the dynamics of salt and water in salt affected soil after the construction of material-filled subsurface drainage

A lysimeter study on the dynamics of salt and water in salt affected soil after the construction of material-filled subsurface drainage

Расчет водопотребления красного клевера с использованием испарения с водной поверхности в условиях Нечерноземной зоны

The subject of research is the development of a method for calculating the water consumption of red clover using data on evaporation from the water surface, aimed at improving the accuracy of its determination and saving water resources, in the watersheds of the nonchernozem zone of Russia. The object of research on the total water consumption of red clover is turfpodzolic soils and soil moisture of watershed areas, when growing fodder crops. Experimental tests were carried out on plots, in lysimeters and laboratories, in different meteorological conditions years. In the processing and analysis of scientifi c research, the doctrine of groundwater fl ow, data from lysimetric studies, and data from field experiments, correlation and regressive analysis were used. Water balance studies were carried out on a scientific basis located in the Moscow region, according to the methodology developed by Yu.N. Nikolsky, V.V. Pchelkin. Experiments conducted in lysimeters and plots in 2015… 2017, served as the basis for the development of a formula for determining the water consumption of red clover using evaporation from the water surface in the watersheds of the non-chernozem zone of Russia.

A lysimeter study on the dynamics of salt and water in salt-affected soil after the construction of material-filled shallow subsurface drainage

A lysimeter study on the dynamics of salt and water in salt-affected soil after the construction of material-filled shallow subsurface drainage

A Modified Lysimeter Study for Phyto-Treatment of Moderately Saline Wastewater Using Plant-Derived Filter Bedding Materials.

The present study focuses on determining the phyto-treatment efficiency for treatment of moderately saline wastewater using organic raw materials, such as rice husk, coconut husk, rice straw, and charcoal. The moderately saline wastewater with total dissolved solids (TDS) concentration up to 6143.33 ± 5.77 mg/L was applied to the lysimeters at the rate of 200 m3 ha–1 day–1 in five different lysimeter treatments planted with Eucalyptus camaldulensis (T1, T2, T3, T4, and T5). T1 was a control without any filter bedding material, whereas rice straw, rice husk, coconut husk, and charcoal were used as filter bedding materials in the T2, T3, T4, and T5 treatment systems, respectively. Each treatment showed significant treatment efficiency wherein T3 had the highest removal efficiency of 76.21% followed by T4 (67.57%), T5 (65.18%), T2 (46.46%), and T1 (45.5%). T3 and T4 also showed higher salt accumulation, such as sodium (Na) and potassium (K). Further, the pollution load in terms of TDS and chemical and biological oxygen demand significantly reduced from leachate in the T3 and T4 treatments in comparison with other treatments. Parameters of the soil, such as electrical conductivity, exchangeable sodium percentage, and cation exchange capacity did not show values corresponding to high salinity or sodic soils, and therefore, no adverse impact on soil was observed in the present study. Also, Eucalyptus camaldulensis plant species showed good response to wastewater treatment in terms of growth parameters, such as root/shoot weight and nitrogen, phosphorus, and potassium (NPK) uptake, plant height, biomass, and chlorophyll content. Root and shoot dry weight were in the order T3 (51.2 and 44.6 g)>T4 (49.3 and 43.5 g) > T5 (47.6 and 40.5 g) > T2 (46.9 and 38.2 g) > T1 (45.6 and 37.1 g). Likewise, the total chlorophyll content was highest in T3 (12.6 μg/g) followed by T4 (12.3 μg/g), T5 (11.9 μg/g), T2 (11.5 μg/g), and the control, that is, T1 (11.0 μg/g). However, the most promising results were obtained for T3 and T4 treatments in comparison with the control (T1), which implies that, among all organic raw materials, coconut and rice husks showed the highest potential for salt accumulation and thereby wastewater treatment. Conclusively, the findings of the study suggest that organic raw material–based amendments are useful in managing the high salts levels in both plants and leachates.

Оптимізація живлення культур в інтенсивній короткоротаційній сівозміні на дерново-середньопідзолистих ґрунтах Полісся

Goal. To determine and investigate the features of optimizing the nutrition of plants of commercially attractive crops using nano-fertilizers on different agrochemical backgrounds. Methods. Lysimetric — to carry out stationary experiment, laboratory — to determine the qualitative indicators, computational — to make an economic evaluation of crop production, mathematical-statistical — to determine the reliability of the results of scientific research. NanoMineralis RK and Nagro nano-fertilizers were used for foliar fertilization of crop rotations. Results. The results of lysimetric studies of the influence of plant nutrition optimization on soil biological activity indicators, nutrient utilization coefficients, the yield of corn, soybean, sunflower, lupine, and productivity of 5-field short-rotary crop rotation obtained during 2016–2020 are presented. It is established that the intensity of CO2 release directly depends on the entry of organic matter into the soil. The combination of the mineral fertilizer system and foliar fertilization of crops with nano-fertilizers (due to the additional entry into the soil of root and crop residues of plants) caused an increase in the soil of biological activity by 8–15% compared to the mineral background. The use of nano-fertilizers promoted more efficient use of nutrients from mineral fertilizers (on average by 26–30%) than without foliar fertilization. The combined use of an alternative regenerative fertilizer system (by-products of the predecessor, green mass of green manure), N62R60K78, and nano-fertilizers provided a high level of crop rotation productivity: harvesting of grain units — 60.1–61.1, feed units — 101.8-103.3, digestible protein — 7.6–7.62 c/ha. Conclusions. Optimization of plant nutrition on low-fertile sod-podzolic soils should combine a holistic set of measures: agrotechnical, organizational (crop rotation), agrochemical (liming, use of all available local organic materials for fertilizer, use of modern mineral fertilizers, and innovative products for foliar fertilization). The deficiency of nutrients in the critical phases of crop development should be overcome by the use of nano-fertilizers in the system of foliar feeding of plants. The combination of mineral fertilizers (N62R60K78 per 1 ha of crop rotation area), by-products and nano-fertilizers of the new generation (NanoMineralis RK and Nagro) increase the biological activity of the soil, nutrient utilization factors from soil and fertilizers, which provides corn grain yield at the level of 9.30–9.43 t/ha, soybeans — 2.54–2.62, sunflower — 2.70–2.73, lupine — 2.83 t/ha, which is 18.5–24.1% higher than at the use of the mineral system of fertilization.

Can the application of farm dairy effluent enhance cadmium leaching from soil?

The application of amendments such as farm dairy effluent (FDE) to soils which contain dissolved organic carbon (DOC) has the potential to increase cadmium (Cd) leaching through the formation of soluble organo-Cd complexes. However, the extent of Cd leaching loss is currently unknown. A lysimeter study measured Cd leaching from coarse and fine-textured Pumice soils amended with either FDE or single superphosphate (SSP) fertilizer. Results showed that despite FDE having a DOC concentration of 3000 mg L-1, concentrations in drainage were low (7.2 to 14.6 mg DOC L-1), probably reduced by microbes and/or sorption onto iron and aluminium oxides in the soil. As a result, there was no significant difference in the amount of Cd lost from the soil amended with FDE (0.79 g ha-1) or SSP (0.70 g ha-1). In comparison, greater amounts of Cd were lost from the fine-textured (0.92 g ha-1) than from the coarse-textured soil (0.57 g ha-1), primarily due to significantly higher Cd concentrations in drainage. The study indicates that a one-off application of FDE at the maximum rate allowed by regulators is unlikely to affect Cd leaching losses, although this still should be confirmed for other soil types that receive FDE.

Impact of loosening and straw addition to the subsoil on crop performance and nitrogen leaching: A lysimeter study.

Poor subsoil properties are difficult to ameliorate and detrimental to soil fertility and crop yield. The effects of loosening (L) and loosening + straw (LS) ∼60 Mg ha-1 into the subsoil (25-40cm depth) on crop yield, water flow, and the nitrogen (N) balance components under bare soil conditions and a barley (Hordeum vulgare L.) crop were investigated in an about 21-mo lysimeter study and compared with a control treatment. Undisturbed soil columns (n=12) were excavated from an agricultural field in May 2016, installed at a lysimeter station, and exposed to outdoor climatic conditions in Uppsala, Sweden, in August 2016. Spring barley ('Makof') was grown between June and September 2017. Total N leaching loads over the 21 mo were high (74-193kg ha-1 ). The LS treatment reduced the N load by 49% (P=.01) and 62% (P=.001) compared with the L and control treatments, respectively. Loosening reduced N load by 25% (P<.07) compared with the control. Emissions of N2 O were low (0.04-0.07kg N ha-1 ), and no differences were observed between treatments. Leaf relative chlorophyll content was lower in the LS treatment than in the L and control treatments (P<.05). Yield was also lowest in the LS treatment (5.8 Mg ha-1 ) and was 7 and 8.5% lower than in the control and L treatments (P>.05), respectively. These results suggest that LS can reduce N leaching. The overall effects of LS on crop performance and N removal and leaching should be further scrutinized in long-term field studies.