Search Results (108)

Subsurface drainage and biochar application are conventional measures for improving saline–alkali soils. However, their combined effects on the fate of nitrogen (N) fertilizers remain unclear. This study investigated the combined effects of subsurface drainage and biochar amendment on the fate of nitrogen (N) in coastal saline–alkali soils, where these conventional remediation measures’ combined impacts on fertilizer N dynamics remain seldom studied. Using ¹⁵N-labeled urea tracing in an alfalfa–soil system, we examined how different drainage spacings (0, 6, 12, and 18 m) and biochar application rates (5, 10, and 15 t/ha) influenced N distribution patterns. Results demonstrated decreasing in drainage spacing and increasing in biochar application; these treatments enhanced ¹⁵N use efficiency on three harvested crops. Drainage showed more sustained effects than biochar. Notably, the combination of 6 m drainage spacing with 15 t/ha biochar application achieved optimal performance of ¹⁵N use, showing N utilization efficiency of 46.0% that significantly compared with most other treatments (p < 0.05). ¹⁵N mass balance analysis revealed that the plant absorption, the soil residual and the loss of applied N accounted for 21.6–46.0%, 38.6–67.5% and 8.5–18.1%, respectively. These findings provide important insights for optimizing nitrogen management in coastal saline–alkali agriculture, demonstrating that strategic integration of subsurface drainage (6 m spacing) with biochar amendment (15 t/ha) can maximize N use efficiency, although potential N losses warrant consideration in field applications. Full article

Salinity stress is a major environmental challenge that adversely impacts the physiological and biochemical processes of pasture, consequently resulting in reduced yields and compromised quality. Biochar amendment has recently emerged as a promising strategy to alleviate the deleterious effects of salinity stress. However, the interactive influences of salinity stress and wheat straw biochar on the physiological, biochemical, and growth characteristics of alfalfa (Medicago sativa L.) remain underexplored. A factorial experiment was conducted using a randomized complete design with five salinity levels (0, 25, 50, 75, and 100 mM NaCl) and three application rates of biochar (0, 25, and 50 g kg⁻¹) to evaluate wheat straw biochar’s potential in alleviating salinity stress in alfalfa. Results showed that salinity stress increased oxidative stress (hydrogen peroxide and malondialdehyde) and reduced chlorophyll fluorescence (maximum quantum efficiency of photosystem II by 1–27%), leading to decreasing photosynthetic parameters, thereby constraining biomass accumulation by 9–77%. Wheat straw biochar amendment under the highest salinity stress, particularly at 25 g kg⁻¹, mitigated oxidative stress by reducing H₂O₂ and MDA levels by 35% and 33%, respectively, while decreasing the antioxidant enzymes activities of CAT, POD, and SOD by 47%, 42%, and 39%, respectively, compared to the control (non-biochar addition). Concurrently, biochar restored the osmoregulatory substance concentrations of proline and soluble sugar by 59% and 33%, respectively, compared to the control. Furthermore, wheat straw biochar amendment increased the net CO₂ assimilation rate by 98%, thereby increasing biomass by 63%. Our study demonstrates that wheat straw biochar can contribute to protecting alfalfa against salinity stress by modulating physiological and biochemical responses. These findings demonstrate that the 25 g kg⁻¹ wheat straw biochar application had the best performance, suggesting this amendment could be a viable strategy for improving alfalfa productivity in salt-affected soils. Future research should explore long-term field applications and the underlying mechanisms of biochar–plant–soil–plant interactions under diverse saline-alkali environments. Full article

Green manure effectively improves soil nutrients and crop yields, yet its partial substitution for chemical nitrogen fertilizer (CF) in maize systems remains underexplored in ecologically fragile Karst landscapes. To assess the effect of alfalfa green manure on maize yield, soil nutrients, enzymes, and microorganisms, we conducted a two-year field experiment comprising eight treatments: four CF levels (100%, 80%, 60%, and 0% of recommended CF) applied alone or combined with alfalfa green manure (CF100, AL_CF100, CF80, AL_CF80, CF60, AL_CF60, CF0, AL_CF0). The results showed that maize grain yield decreased with the sole reduction of chemical N fertilizer. Compared to the CF100 treatment, the AL_CF100 and AL_CF80 treatments significantly increased grain yield by an average of 21.8% and 16.9%, respectively. Additionally, the AL_CF60 treatment maintained maize grain yield in 2020 and significantly increased it in 2021. The AL_CF100 treatment significantly enhanced soil available N (AN) content, while soil Olsen-P (SOP) content and soil quality index (SQI) were significantly improved in the AL_CF100, AL_CF80, and AL_CF60 treatments. Alfalfa green manure application had no significant effect on soil bacterial and fungal communities. However, the CF rates positively influenced the relative abundances of bacterial phyla (Bacteroidota, Myxococcota, and Patescibacteria) and genera (Intrasporangium, Streptomyces, and Quadrisphaera), as well as fungal genera (Exophiala and Setophoma). α-Diversity analysis revealed that partial substitution of CF with alfalfa green manure did not significantly affect soil bacterial diversity (Ace, Shannon, and Sobs indices) or richness (Chao value). In contrast, chemical N fertilizer rates significantly altered the β-diversity of both bacteria and fungi. The soil AN, AK, sucrase activity, and the relative abundances of Bacteroidota, Streptomyces, and Instrasporangium showed significant positive relationship with maize grain yield. This study demonstrates that substituting 20% CF with alfalfa green manure optimizes maize productivity while enhancing soil health in Karst agroecosystems. Full article

Soil fertility has an important impact on orchard yield and quality, and sandy soil limits the economic yield of orchards due to its low water and fertilizer retention capacity. Although biochar and alfalfa planting have been widely utilized separately in soil improvement, few studies have examined the effects of combined alfalfa planting and biochar application on jujube orchard soils. This study investigates the effects of alfalfa planting alone and alfalfa planting combined with different levels of biocarbon addition on soil properties. A field experiment was conducted in a jujube orchard in Yanchuan County, Shaanxi Province, with four treatments: clear tillage control (CK), alfalfa planting only (B1), alfalfa planting + 1.5 kg·m⁻² biocarbon (B2), and alfalfa planting + 3 kg·m⁻² biocarbon (B3). The results show that planting alfalfa significantly increased soil moisture content (SMC) and soil organic matter (SOM) content by 27.79% and 17.65%, respectively, and biochar addition significantly increased soil carbon, nitrogen, and phosphorus content by 8.11–37.7%, enhanced the soil moisture content (SMC) by 98.13–100.22%, promoted the growth of alfalfa, and increased vegetation cover (p < 0.05). The combination of biochar and alfalfa improves soil fertility more effectively than alfalfa alone. It can increase the soil N and P nutrient contents, improve soil available nutrients, promote alfalfa growth in a short period, and provide a feasible solution for soil improvement in the future. Full article

Coastal saline–alkali soils, characterized by poor structures and low fertility, limit sustainable agricultural development. This study aimed to investigate how green manure application influence soil aggregate stability and soil organic carbon (SOC) sequestration in such coastal saline soils. Field experiments were conducted by comparing the following five treatments: (1) control (CK); (2) ryegrass full incorporation (RF); (3) ryegrass mulching (RM); (4) alfalfa full incorporation (AF); (5) alfalfa mulching (AM). The results demonstrated that green manure application significantly increased large macroaggregate (>2 mm) proportions by 20.60–56.70% while reducing microaggregates (<0.25 mm) by 24.35–68.43%. SOC increased across 0–40 cm soil depth, primarily driven by large macroaggregates and microaggregates, which contributed 23.7–73.5% and 34.8–91.4% of the total increase, respectively. Mulching treatments (AM/RM) increased surface SOC sequestration, while full-incorporation practices (AF/RF) boosted subsoil SOC stocks. These results highlight green manure application as an effective strategy to rehabilitate coastal saline soils by enhancing aggregate stability and SOC sequestration, providing technical guidance for saline soil rehabilitation in coastal saline regions. Full article

Coastal saline–alkaline soils are characterized by high salinity and poor permeability. Subsurface drainage and biochar amendment are both practical methods, and their combination may overcome the limitations of individual measures and achieve rapid desalination and soil improvement. To evaluate the impact of different subsurface drainage spacing and biochar amendment on soil properties and crop yield, the salt-tolerant plant “alfalfa” was used as the main material. We designed four drainage spacing treatments (0 m (CK), 6 m (S1), 12 m (S2), and 18 m (S3)) and three biochar amendment rates (5 t ha⁻¹ (C1), 10 t ha⁻¹ (C2), 15 t ha⁻¹ (C3)). Soil physical indicators, salinity, and alfalfa yield are measured. The results showed that smaller drainage spacing and higher biochar amendment rates were beneficial for soil improvement, including bulk density, porosity, and field capacity. The experimental treatments affected the entire soil profile (0–80 cm), with subsurface drainage showing a greater impact on reducing salinity than biochar amendment. The S1 treatment had the most significant yield-increasing effect compared to other spacings. The increase in the biochar amendment rate promoted alfalfa yield, particularly for the first harvest. Overall, the results indicated that the drainage spacing of 6 m and the biochar amendment of 15 t ha⁻¹ were most beneficial in improving soil properties in the plow layer and promoting alfalfa yield in saline–alkaline soils. Full article

Mixed sowing of forage grass can reduce soil erosion, improving forage nutritional composition, enhancing grassland productivity, and increasing community stability. It addresses issues faced by sown pasture, including a lack of diversity in planting patterns, low resource utilization efficiency, and poor sustainability. However, the effects of mixed sowing on forage yield and water use efficiency (WUE) vary depending on regional environmental conditions, management practices, and temporal factors. Based on publicly available field experiment data, this study utilized meta-analysis to quantitatively examine the effects of mixed sowing on forage yield and WUE in China. Additionally, a random forest model was employed to analyze the main influencing factors. The results showed that, compared with monoculture, mixed sowing significantly improved forage yield and WUE, with average increases of 58.3% (confidence interval: 44.3–72.3%) and 32.0% (confidence interval: 19.2–44.8%), respectively. Regarding yield, the effect of mixed sowing was the most pronounced in Shaanxi. Optimal conditions included experiments conducted during 2006–2008, annual precipitation of 200–600 mm, soil pH of 4−5, average annual temperature of 10–15 °C, altitudes below 2000 m, alfalfa (Medicago sativa) and Bromus inermis as the forage combination, two species in the mixture, a legume-to-grass species ratio of 1:1, a total seeding rate of 40–50 kg·ha⁻¹, and mixed sowing in the same row. For WUE, significant effects were observed in Gansu under the following conditions: experiments conducted during 2018–2020, annual precipitation of 400–600 mm, an average annual temperature of 5–10 °C, a soil pH of 8–9, altitudes of 1000–2000 m, oats (Avena sativa) and peas (Pisum sativum) as the forage combination, two species in the mixture, a legume-to-grass species ratio of 1:1, a total seeding rate of <50 kg·ha⁻¹, and mixed sowing in alternate rows. The random forest model indicated that the effects of mixed sowing on forage yield were primarily influenced by annual precipitation, average annual temperature, and experimental region. In contrast, the effects on WUE were mainly determined by forage combination, species type, and the legume-to-grass species ratio. This study provides a reference for enhancing alfalfa productivity and achieving efficient water use. Full article

Water-based resin-coated controlled-release fertilizer (CRF) is valued for its safety, environmental benefits, and water absorption/retention properties. To improve the productivity of alfalfa (Medicago sativa L.) and the soil quality in coastal saline–alkali land at the Yellow River Delta, in this work, we carried out field experiments to study how the application of CRF (water-based resin-coated urea) and soil conditioner, both developed in-house, affected the alfalfa harvest and the soil properties. The following five treatments were tested from 2022 to 2023: T0, no fertilization; T1, urea with P&K fertilizers; T2, CRF with P&K fertilizers; T3, urea, P&K fertilizers, and soil conditioner; T4, CRF, P&K fertilizers, and soil conditioner. The results showed that the simultaneous application of CRF and soil conditioner (i.e., T4) had the most obvious effect on improving the yield and quality of alfalfa. In 2022, T4 had 6.3% higher total alfalfa yield than T0. In 2023, T4 had 14.2% and 8.4% higher total alfalfa yield than T0 and T1, respectively. The alfalfa from T4 had higher crude protein content and relative feeding value (RFV), lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) content. The combined application of CRF and soil conditioner reduced the salinity of the surface soil and increased the soil organic matter, available nitrogen, and phosphorus at the 0~40 cm layer. Therefore, the application of soil conditioner and CRF can improve the use of coastal saline–alkali land for the cultivation of alfalfa. Full article

The addition of phosphorus fertilizer plays a critical role in improving alfalfa yield and quality. However, improper application may lead to resource waste and environmental pollution, and its effects are influenced by multiple factors. This study quantitatively analyzed the effects of phosphorus fertilization on alfalfa yield, crude protein (CP) content, acid detergent fiber (ADF) content, and neutral detergent fiber (NDF) content and their major influencing factors using a meta-analysis method by integrating data from published field experiments. The results showed that, compared to no phosphorus application, phosphorus fertilization increased alfalfa yield, CP content, and NDF content by 19.0% (confidence interval [CI]: 15.4–22.6%), 7.2% (CI: 0.1–14.9%), and 7.2% (CI: 0.1–14.9%), respectively, while reducing ADF content by 3.3% on average (CI: 0.9–3.3%). In Shandong, Jilin, and Hebei, where the soil pH is 7–8, annual precipitation is 200–400 mm, annual mean temperature is above 4 °C, and altitude is 500–1000 m, alfalfa yield improved after applying calcium phosphate or single superphosphate with a P₂O₅ content of 0–20% at a rate of 100–200 kg·ha⁻¹, along with nitrogen > 100 kg·ha⁻¹, and when both the test and establishment periods were 2 years. In Xinjiang, in regions with an annual mean temperature of 6–8 °C and an establishment duration of 3 years, phosphorus fertilization improved alfalfa quality. This study provides references for enhancing alfalfa productivity and efficient utilization of phosphorus nutrition. Full article

Flower strips (FSs) are an effective way to support the sustainable development of agricultural land. Properly managed FS on agricultural fields provide stable habitats for local arthropod populations, but over the years, it can be colonized by plants from the soil seed bank and then become a nuisance to surrounding crops. The aim of this study was to assess the botanical composition of FS in one year after establishment and to analyze the local population of Carabidae, most of which are predatory. Inventory of flowering plants in situ was made regularly from the beginning of June to the end of July, while beetles were collected in mid-July and August. It was found that plant species from the sown seed commercial mixture continued to dominate in the second year, but the proportion of species from the soil seed bank was also noted, ranging from 7.41% to 39.88%. It was concluded that Trifolium pratense L. and Chrysanthemum leucanthemum L. should be particularly recommended for strip sowing in the observed habitats. The species diversity (H’) of Carabidae was higher in the FS than in the cultivated fields. However, when comparing the Shannon–Wiener index for wheat and FS, regardless of time observation, no significant differences were noted. The most abundant ground beetle in the FS was Harpalus rupees, a universal predator that also feeds on weed seeds. Significantly fewer species and individuals of Carabidae were found in the alfalfa field than in the FS and wheat fields. The number of Carabidae was significantly higher in August than in July. Full article

Mobile drip irrigation (MDI) systems integrate the technological advantages of center-pivot irrigation (CPI) systems and drip irrigation systems, boasting a high water-saving potential. To further enhance water use efficiency in alfalfa production in northern China, this preliminary study verified the accuracy of the HYDRUS-2D soil water movement numerical model through field experiments. Using the numerical model, four drip-line installation distances (60, 75, 90, and 105 cm), three deficit irrigation thresholds (45–50% FC, 55–60% FC, and 65–70% FC), and four irrigation depths (70% W, 85% W, 100% W, and 115% W) were set to simulate root water uptake, soil surface evaporation, total irrigation amount, and deep percolation during the entire growth cycle of alfalfa, respectively. Objective functions were constructed according to the simulation results, and the NSGA-II algorithm was used for multi-objective optimization of the deficit irrigation schedule. The preliminary results indicated that HYDRUS-2D can accurately simulate soil water movement under MDI systems, as the RMSE values of soil water content at all measured depths were less than 0.021 cm³/cm³, with the NRMSE values being below 23.3%, and the MAE values below 0.014 cm³/cm³. Increasing the deficit irrigation threshold from F1 to F3 enhanced root water uptake by 12.24–15.34% but simultaneously increased the total irrigation amount, soil surface evaporation (by up to 29.58%), and the risk of deep percolation; similar trends were observed with increasing irrigation depth. The drip-line installation distance had no significant impact on irrigation performance. The NSGA-II multi-objective optimization algorithm was used to obtain Pareto-optimal solutions that balance conflicting objectives. For this case study, a drip-line installation distance of 105 cm, a deficit irrigation threshold of 50–55% FC, and an irrigation depth of 112% W were recommended to achieve balance among the various optimization objectives. This study provides a preliminary framework for optimizing MDI systems and irrigation strategies. However, since a deeper root distribution (>80 cm) was not investigated in this study, future research incorporating deeper root zones is required for developing more comprehensive irrigation scheduling suitable for typical alfalfa cultivation scenarios. Full article

It has been assumed that the long-term impact of a diversified soil use system (SUS) and the continuous application of manure and/or mineral fertilizers (NPK) affects the sustainability of soil fertility components. This influence is manifested through the content and distribution of nutrients, as well as some bioavailable heavy metals in the soil. This hypothesis was verified in 2022 in a long-term field experiment that started in 1957. It consisted of a seven-course crop rotation: potato–spring barley–winter triticale–alfalfa–alfalfa–winter wheat–winter rye and monocultures of these crops plus black fallow. The studies were carried out on three separate fields: black fallow (BF), winter wheat grown in monoculture (WW-MO), and crop rotation (WW-CR). Each of these experimental objects consists of five fertilizer variants (FVs) fertilized in the same way every year: absolute control (AC)—variant without fertilizers for 75 years; farmyard manure—FM; mineral fertilizers—NPK; mixed variant—NPK + FM; mineral fertilizers plus annually applied lime—NPK + L. The second factor was the soil layer: 0.0–0.3 m, 0.3–0.6 m, or 0.6–0.9 m. The obtained results clearly indicate that long-term fertilization with NPK + FM, especially in rotation with legumes, strengthens the eluviation/illuviation processes, decreasing the sustainability of soil fertility. Liming is a factor stabilizing the content and distribution of silt and clay particles in the soil. The key factor determining the content and distribution of micronutrients and heavy metals in the soil was the content of organic carbon (C_org). Its content decreased in the following order: WW-CR (13.2 ± 5.8) ≥ WW-MO (12.3 ± 6.9) > BF (6.6 ± 2.8 g·kg⁻¹). The large variability resulted from a distribution trend with soil depth, which increased as follows: MO ≥ CR > BF. FVs with FM had the highest C_org content. NPK, regardless of the long-term soil use system (SUS), had the lowest content. Among the elements studied, the key one impacting the content of both micronutrients and heavy metals was iron (Fe). The Fe content decreased in the order BL (100%) > WW-MO (90.5%) > WW-CR (85%). The opposite tendency was found for the remaining elements, the content of which was consistent with the content of C_org, which was the highest in CR. The strongest impact of Fe, modified by the SUS, was found for Zn, Pb, and Cd. Despite the differences observed between SUSs, fertilization variants, and soil layers, the content of Fe and Mn was in the medium class, while Zn and Cu were in the high class of availability. The content of Ni was the highest for NPK + FM in WW-CR. The content of Pb was weakly affected by the long-term SUS but showed a strong tendency for accumulation in the topsoil layer. The content of Cd was the highest in BF, where it exceeded the threshold of 0.27 mg·kg⁻¹. The long-term diversified SUS, as the main factor determining the sustainability of soil fertility, makes it possible to indicate the directions of humus accumulation and its distribution in the soil. It turned out to be a key factor, but in cooperation with Fe, it determined the content of micronutrients and bioavailable heavy metals in the soil. Full article

The degradation of black soil cropland has occurred to varying degrees in the northern agropastoral ecotone. Crop–forage rotation is an effective way to improve soil quality, with Medicago being the preferred perennial legume. The C, N, and P stoichiometric ratios are key indicators of soil quality and organic matter composition, reflecting the status of the internal C, N, and P cycles in soil. This study aims to investigate the ecological stoichiometric ratios of Medicago grassland soils with different planting durations, explore the regulatory effects of nitrogen fertilizer on soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) content, and assess the impacts of these changes on the Medicago grassland ecosystem. This study was conducted on the long-term cultivated grassland core experimental platform of the Hulunber National Field Station. Based on forage yield and soil nutrient measurements, field-based observations and laboratory analyses were carried out. Medicago × varia was the study subject, with different nitrogen fertilizer treatments: CK (0 kg N ha⁻¹), N₇₅ (75 kg N ha⁻¹), and N₁₅₀ (150 kg N ha⁻¹). A randomized block design was adopted. Variance analysis, boxplot statistics, and scatterplot fitting methods were used to examine soil properties and assess the effects of nitrogen application on the C, N, and P stoichiometry of soils in established perennial Medicago grasslands. The results indicate that, based on the growth characteristics of alfalfa, soil nutrient dynamics, and its effectiveness in improving soil quality, the optimal rotation period for alfalfa in the northern agropastoral ecotone is 4–5 years, but it can also be shortened to 3 years. Soil carbon, nitrogen, and phosphorus contents are significantly influenced by the planting duration. As the planting years increase, soil carbon and nitrogen contents first increase and then decrease, while soil phosphorus content initially decreases followed by a slight increase. Soil pH gradually rises with both planting years and soil depth. Both low and high levels of nitrogen fertilizer application reduce soil organic carbon concentration (by 0.40% and 10.14%, respectively). Low nitrogen fertilizer application increases soil nitrogen concentration (by 1.50%), whereas high nitrogen fertilizer application decreases it (by 7.6%). Both nitrogen levels increase soil phosphorus concentration (by 36.67% and 35.26%, respectively). For soil from an alfalfa grassland planted for 8 years, the carbon-to-nitrogen ratio ranges from 9.08 to 9.76, the carbon-to-phosphorus ratio from 13.00 to 151.32, and the nitrogen-to-phosphorus ratio from 1.65 to 17.14. In summary, alfalfa yield is primarily influenced by the nitrogen fertilizer application rate, planting duration, stoichiometric ratios, and pH. Nitrogen fertilizer application has a positive regulatory effect on soil stoichiometric ratios. The annual yield can reach 8.94 to 10.07 tons per hectare., but phosphorus remains a limiting factor. These findings provide crucial data for understanding the impact of ecological stoichiometry on crop–forage rotation cycles, as well as optimal land use and quality improvement. Full article

Soil microbial communities play an important role in driving diverse ecosystem functions and ecological processes and are the main driving force for maintaining biogeochemical cycles. To investigate the effects of nitrogen fertilizer addition on soil microbial community characteristics and ecosystem multifunctionality in alfalfa fields, a field experiment was conducted in the semi-arid region of the Loess Plateau. Ecological network analysis revealed a strong cooperative relationship among bacterial community species under the N100 treatment, while a strong competitive relationship was observed among fungal community species under the N50 treatment. Furthermore, compared with the control check, the soil carbon nutrient function, ecosystem multifunctionality and grassland productivity of N150 treatment increased by 45.17%, 34.01%, and 7.92%, while the soil phosphorus function decreased by 13.44%. Additionally, soil pH significantly influences ecosystem multifunctionality, soil carbon nutrient function, and grassland productivity. Soil water content notably affects the soil phosphorus nutrient function, while soil microbial diversity has a significant impact on grassland productivity and soil potassium nutrient function. The above results suggest that alterations in soil nutrient levels influence ecosystem multifunctionality by regulating microbial community diversity, offering new insights into the mechanisms by which nutrients impact soil microbial communities and ecosystem properties. Full article

An alternative method of plant nutrition involves the utilization of different by-products. In this study, a combination of two by-products was applied to investigate this method: fermented deproteinized alfalfa juice (FDAJ), a by-product of alfalfa leaf protein production, and fly ash filtrate from a wood-fired power plant. A pot experiment was conducted with winter wheat in an open-sided greenhouse in sandy soil. The aim was to evaluate the efficacy and usability of the combination of these by-products (SFDAJ) for enhanced plant nutrition via spraying or irrigation. Prior to overwintering, photosynthetic pigments, relative chlorophyll content, specific leaf area, and shoot dry weight were measured. At full maturity, we determined morphological parameters, yield, and the element content of the grain. Significant differences were observed between treatments at full maturity. The application of SFDAJ resulted in 73.2% of the yield having the optimal nutrient supply. Compared to the treatment with no nutrients added, the application of SFDAJ increased yields by 260%. Our results show that SFDAJ alone is suitable for providing enhanced nutrient supply in soils with good nutrient supply or in extensive cultivation technology. When supplemented with fertilizer, it can be used on soils with low nutrient supply or in intensive cultivation technology. Based on our results of field applications of SFDAJ, the addition of 10 v v^−1% FDAJ via irrigation is recommended. Full article