Poor Soil Research Articles

Climate–change adaptations can raise cropping’s contribution to household income

ABSTRACT A two-stage fractional regression model is applied to 998 farm observations from Ghana to estimate how three climate-change adaptation practices influence the contribution of crop revenue to household income. The first stage, analysing land selection, shows that farmers in peri-urban areas who cultivate drought-tolerant varieties raise their crops on poor soils, but male farmers, who cultivate large farms and have access to inorganic fertiliser (on credit), have the benefit of fertile soils. The second-stage shows that crop substitution, use of drought-tolerant varieties, and variation in planting dates increase the contribution of crop revenue to household income. Therefore, public and non-state institutions should continue to invest in technology transferat the same time, addressing farm-level constraints on the adoption of proven agricultural innovations.

Eucalyptus pellita harvest residue management in sandy tropical soils – nutrient content, decomposition and potential emissions from burning

Plantation forestry on sandy, nutrient poor soils has been developed over the last few decades in seasonally dry tropical monsoon environments. Despite the known benefits of harvest residue conservation between rotations in temperate climes, there are very few studies around the world on Eucalyptus harvest residue management in tropical areas. In Northern Australia on Melville Island 30,000-hectares of Acacia mangium is planned to be converted to Eucalyptus pellita. E. pellita harvest residues comprise high loads of stringy bark, leaves and twigs, posing a fire risk throughout the annual 6-to-8-month dry season in Australia's monsoonal tropics. In this environment, quantifying and demonstrating the anticipated benefits of residue retention is important for determining appropriate responses to fire risk.A 4-hectare experimental trial of 12-year-old E. pellita was cut with trees moved intact to the coupe edge and processed for woodchips. The tree residues from the roadside chipper were pushed back over the site. A total of 35 Mg ha−1 of harvest residue was left on the site, mainly comprised of bark (24.5 Mg ha−1 or 60 % of the total residue mass). Although the leaf and branch residues contained higher concentrations of N, Ca, Cu, K, Mg, Mn, P, and Zn than bark, stem and woodchips, bark N (51.5 kg ha−1) was twice foliage N (26.9 kg ha−1), and contributed to more than 50 % of residue N.Harvest residue bark, leaves and twigs were sampled for a litterbag decomposition study of mass loss on the harvested site. After 10 months about 80 % of bark original weight remained on site (20 % mass loss), compared to about 55 % of the leaves/twigs remaining (45 % mass loss).The potential non-CO2 emissions from the burning of E. pellita harvest residues were estimated at 12.3 Mg CO2-eq ha−1 or 3.35 Mg C ha−1, with the majority of emission arising from the smoldering of bark residues. This study discusses the implications of either retaining or burning harvest residues – for plantation long-term sustainability on sandy tropical sites, and for greenhouse gas emissions.

The LTAR Grazing Land Common Experiment at Archbold Biological Station-University of Florida.

The Archbold Biological Station-University of Florida (ABS-UF) Long-term Agroecosystem Research (LTAR) site lies in the heart of south-central Florida, representing subtropical humid grazing lands in North America and globally. Beef producers in this region face challenges due to climate variability, limited nutritive value of forages, poor soils, public concerns about water quality and greenhouse gas emissions, management trade-offs, economic uncertainty, and increasing urban encroachment. The ABS-UF Common Experiment, co-designed with stakeholders, will assess innovative management systems in comparison to prevailing management systems on key indicators of sustainability. Innovative management systems being tested are alternative fire (frequency and spatial extent) and grazing practices (stocking rate and system). The common experiment framework was implemented across a management intensity gradient spanning from native rangeland to cultivated pastures, including embedded wetlands. Issues that have arisen to date include difficulties in implementing prescribed fire and reduced productivity in cultivated pastures associated with innovative management, which led to an adjustment of the experimental treatment. A stakeholder advisory council will codesign future alternative treatments and guide experimental changes in this long-term experiment. Stakeholder engagement efforts revealed research priorities centered on financial strength, carbon (C) and greenhouse gas emissions, and water quality. Stakeholders are also interested in testing emerging technology such as the utility of virtual fencing. Results from ABS-UF provide a unique perspective from subtropical humid grazing lands for continental-scale cross-site synthesis on sustainable agroecosystems across LTAR.

Leafina: Potency of Kakawate leaves, fishbone meal and saba banana peel compost soil amendment to the water holding capacity of loam soil

In tropical regions like the Philippines, drought susceptibility is caused by high evaporation rates and poor soil water retention. To deal with this, soil amendments are crucial, enhancing soil properties to aid plant growth. In this study, LeaFiNa, a compost soil amendment composed of Kakawate leaves (KL), fishbone meal (FB), and Saba banana peels (BP) was introduced, aiming to boost soil water holding capacity (SWHC) of loam. Different LeaFiNa ratios were tested, including 3KL:1FB:2BP, 6KL:4FB:1BP, and 3KL:8FB:1BP, alongside vermicast and commercial soil amendment (neem cake) as positive controls, and plain loam soil as the negative control. Percolation method and pressure plate extraction was performed. One-way ANOVA showed a significant difference among the experimental treatments (α=0.05) in which 6KL:4FB:1BP ratio emerged with the highest SWHC of 49.60%. Meanwhile, Tukey’s HSD test revealed no significant difference between 6KL:4FB:1BP and vermicast, yet a significant difference with the negative control. Moreover, the experimental treatments, particulalry the 6KL:4FB:1BP, also exhibited ideal results on other SWHC parameters such as the soil moisture content at saturation and wilting points, and in terms of gravitational water and plant available water. These findings suggest the LeaFiNa’s potential in alleviating drought stress in tropical soils by enhancing water retention, offering promising outcomes for sustaining agricultural productivity in water-scarce regions.

Feasibility and application of soil reconstruction technology for farmland consolidation in China's Loess Plateau

With the widespread implementation of farmland consolidation projects globally, the poor soil quality of newly created farmland (NCF) has become a significant bottleneck hindering the sustainable progress of such projects. Soil reconstruction technology (SRT), an innovative method to rapidly and effectively enhance the soil quality of NCF, has emerged as a prominent area of research in modern agricultural development. The Loess Plateau in China is highly susceptible to soil erosion and ecological degradation, making it a prime location for large-scale farmland consolidation efforts over the years. Investigating the practical feasibility and application potential of SRT can offer crucial technical insights for project implementation. This study conducted a field experiment in the Yangjuangou catchment of Yan’an City to explore the effects of soil mixing measures on soil properties and crop yield. Results indicated significant improvements in soil particle size distribution, physicochemical properties, and maize yield of NCF following soil reconstruction through the mixing of Malan Loess. Furthermore, the application of SRT demonstrated practical feasibility for farmland consolidation, leading to maximum crop yield and optimal ecological and economic benefits. The study also deliberated on the implications of farmland consolidation for land use policy and its contribution to sustainable agricultural development.

ANALISIS STABILISASI TANAH LEMPUNG MENGGUNAKAN CAMPURAN ABU SEKAM PADI TERHADAP NILAI KUAT GESER TANAH

The main aim of stabilization is to change the technical properties of the soil itself, such as the compressibility and bearing capacity of the soil. Based on the results of testing the physical and mechanical properties of the original soil of Sambirejo Village, Puhpelem, Wonogiri according to the ASSHTO method, the original soil is included in group A-7-6, which is medium to poor clayey soil material. Meanwhile, according to the USCS method, it is included in the CH group, namely organic clay with high plasticity, fat clays. After conducting further research with variations in the rice husk ash mixture of 0%, 5%, 10%, 15%, and 20%, the results showed that the soil physical test showed the values of water content (W), liquid limit (LL), plasticity index (PI ), and the percentage passing filter No. 200 experienced a decrease with increasing percentage of addition of rice husk ash with yield figures on original soil of 53.00%, 52.00%, 15.32%, 62.00% while on original soil with a mixture of 20% rice husk ash obtained results of 50.11%, 41.10%, 1.65%, 51.00 %. Meanwhile, the specific gravity (Gs), plasticity limit (PL), and shrinkage limit (LL) increased with increasing percentage of rice husk ash addition with the yield figures on the original soil being 5.409%, 36.68%, 12.65%, while on the original soil with a mixture of rice husk ash 20% rice obtained yields of 6.071%, 39.45%, 26.89%. Based on the results of the Direct Shear Test, the soil experienced an increase with each addition of rice husk ash. The highest Direct Shear Test value occurred in 20% mixed soil, namely 0.583 kg/cm2 and the lowest Direct Shear Test value occurred in original soil, namely 0.394 kg/cm2.

ANNUAL GROWTH RING CHARACTERISTICS OF QUERCUS CERRIS (L.) TREES GROWN UNDER DIFFERENT CONDITIONS

The study examined the effect of stand composition and soil quality on radial growth of Quercus cerris (L.) grown in Vas County in Hungary. Twelve trees were randomly harvested, and the sampled wood pieces were extracted from the breast-height portion. Wood strips were machine-sanded, scanned for analysis in ImageJ. Climate data were obtained from a database of the Hungarian National Metrological Service. Mean annual-ring width was larger for trees harvested from mixed species planting site. Overall, annual-ring sizes for trees harvested from pure species stand that thrive on poor soils exhibited wider variation (62%). The same plot of trees had a latewood width variation of 82%. Precipitation correlated positively with annual-ring size with weak to moderate coefficient (0.13 – 0.32), whereas maximum temperature negatively correlated with annual-ring size on moderate coefficient (-0.42)

Regulating Cotton Growth via Rhizobium Species

Unpredictable precipitation is a common problem for plant growth in India’s Deccan plateau, which is known for its poor soil and frequent droughts. Critical to the regulation of plant diseases and the enhancement of plant growth are root-colonizing rhizobacteria like Rhizobium. Isolating productive Rhizobium species from soil around the Eturnagram region’s cotton rhizosphere was the goal of a study carried out at Palamuru University. Rhizobium variant-5, currently known as Rhizobium sp. PKS [NCBI-OK663003, NCMR-MCC4960], was one of five different strains of Rhizobium isolated using the top layer method. It showed strong support for the growth of six different cotton cultivars. Out of the six cotton varieties tested, the Mahyco cultivar had the lowest proline levels while having higher amounts of IAA, proteins, chlorophyll, and sugars. The effectiveness of Mahyco was confirmed by experimental field testing conducted in four distinct cotton agricultural soils of Mahabubnagar District using Rhizobium sp. PKS [NCBI-OK663003, NCMR-MCC4960]. Deep black soil showed improved phytohormone synthesis and good biochemical alterations, whereas shallow black soil showed that the strains considerably enhanced plant development. Based on these results, the novel Rhizobium sp. PKS could be used as a bioinoculant in cotton fields on the Deccan plateau, which could improve agricultural yields despite the harsh conditions.

Exploring farmer’s assessment of soil quality and root yield in cassava-based cropping systems

Farmers’ knowledge of soil quality and yield assessment were evaluated among cassava farmers in southwestern Nigeria. Data were collected on farmers’ demography, farming experience, criteria for selecting a site for cassava cultivation and preferences for those criteria, farmers’ methods of yield prediction and how it compares with the scientific approach, farmers’ agronomic knowledge and how it relates to the realities of climate change and soil fertility decline. The modal age class of the farmers is 45–55 years, and most of the farmers are male. The results show that farmers use a combination of soil and vegetation-based criteria to assess soil quality from which the decision to cultivate a given land is made. Among the soil-based criteria, soil drainage, colour, and depth rank the most and most used. Most of the farmers assessed yield before harvesting through green healthy leaves (25 %), large and shiny stems (25 %) and soil cracks (50 %). The predicted and measured cassava yields on farmer-managed farms were comparable, with an R2 of 0.63, although farmers overestimated the cassava root yield. There is a unanimous consensus among farmers that yield has declined in the last decade, with a mean of 36 %. The main cause of yield decline was attributed to declining rainfall and poor soils. Our study concluded that farmers have a good understanding of soil health and cassava agronomy through a process of trial and error and ingenuity as farmers’ local indices were consistent with conventional soil health indicators. It was suggested that, by recognising and incorporating traditional methods used by farmers to assess soil quality, we could enhance soil management strategies and raise productivity at the farm level.

English

The district Toba Tek Singh is located in the center of Punjab province. It occupies 2nd important position in national citrus production after Sargodha, with citrus orchard area of 11412 hectares and annual production of 160758 tons. Citrus productivity in Pakistan, in general, and Toba Tek Singh, in particular, is far below its its potential which could be attributed to several factors but poor soil health and inadequate soil fertility may be considered an important reason. A comprehensive nutrient indexing survey of thirty citrus orchards grown in different parts of district Toba Tek Singh was conducted to evaluate the soil characteristics and plant nutrient status. GPS coordinates of selected sites were recorded prior to sampling. Soil samples were collected at 0-20 cm, 21-40 cm and 41-60 cm depth using standard procedure. Five soil samples were collected from each site to get a composite sample for each depth. The leaf samples were collected from the 7-month-old non-fruiting branches of plants around the tree canopy during the month of September, 2022. Five healthy and uniform citrus trees were sampled from each site to get a composite leaf sample. The soil samples were analyzed for pH, electrical conductivity (EC), soil organic matter (SOM) and calcium carbonate (CaCO3). The soil and leaf samples were analyzed for macro and micronutrients. It was found that most of orchard soils of district Toba Tek Singh were moderately alkaline (pH 7.52-8.90), slight to strong calcareous (2-15% CaCO3), non-saline (0.77-3.0 dS m-1 EC) and low in SOM (0.23-1.49%) with low to medium nitrogen (0.01-0.06%) and phosphorus (0.58-10.52 mg kg-1) while medium to high potassium (56.47-315.34 mg kg-1). The sampled soils were low to marginal in boron (0.09-0.72 mg kg-1), copper (0.05-0.59 mg kg-1), iron (0.23-10.75 mg kg-1) and zinc (0.03-1.83 mg kg-1) while adequate in manganese (1.35-26.20 mg kg-1). Leaf analysis revealed that almost 50% orchards were deficient in phosphorus (0.05-0.23%) and potassium (0.40-1.76%), while having low to marginal values of copper (1.96-20.99 mg kg-1), zinc (4.13-31.96 mg kg-1), boron (3.12-95.40 mg kg-1), manganese (42.62-96.46 mg kg-1) but adequate iron (171-552 mg kg-1). The surveyed orchard soils were mostly alkaline calcareous, deficient in organic matter and having low to moderate macro and micronutrients.

Evaluation of push-pull technology for pest and soil fertility management on maize in north western Ethiopia

Maize (Zea mays L.) production in north western Ethiopia is severely constrained by the parasitic weed striga (Striga hermontica), the stemborer (Busseola fusca) pest, and poor soil fertility due to continuous mono cropping. An intercropping system known as push-pull technology is a novel soil and pest management strategy for improving soil fertility and controlling agricultural pests by using repellent "push" plants (such as desmodium, Desmodiumintortum)and trap "pull" plants (such as napier grass, Pennisetum purpureum). The aims of the study were (i) to evaluate the effectiveness of the push-pull technology against stemborer and striga infestation, (ii) to investigate the impact of the push-pull technology on improving grain yield, and (iii) to assess effect of the push-pull technology on soil fertility. The study was conducted in 2017 and 2018 cropping seasons in 3 districts in north western Ethiopia. Three farmers from each district, who practiced the technology, were randomly selected for the study. Each farmer had a set of two treatments (plots): a push-pull technology (PPT) and maize monocrop (MC) treatments. Data were collected on the percentage of maize plants damaged by stemborers, the number of striga plants that emerged, plant height, grain yield, available phosphorus (P), available potassium (K), total nitrogen (TN), organic carbon (OC), organic matter (OM) and bulk density (BD). There were significant reduction in stemborer damage (2.8 %) and striga count (4.1 Striga plants/m2) in the push-pull treatment compared to the maize monocrop plots (15.4 % and 21.8 striga plants/m2, respectively). Maize plant height (2.34 m) and grain yield (5.3 t ha−1) were significantly higher in the push-pull plots as compared to the sole crop (1.9 m and 3.0 t ha−1, respectively). Similarly, there were significantly higher P (20.06 mg/kg soil), K (406.86 mg/kg soil), TN (2.5 g/kg soil), OC (42.9 g/kg soil), OM (73.8 g/kg soil) levels considered to be moderate to high fertility status in the push-pull as compared to monocrop plots (11.17 mg/kg soil, 347.93 mg/kg soil, 1.6 g/kg soil, 29.8 g/kg soil, and 51.2 g/kg soil, respectively) which is rated from low to moderate soil fertility level. Moreover, bulk density was significantly lower in PPT (0.92 g/cm3) than in MC (0.95 g/cm3) plots. This suggests that push pull technology is effective in reducing striga and stemborer damage and improves soil fertility status which results in better grain yield.

The Effect of Liquid Organic Fertilizer from Kepok Banana Humps on Cayenne Pepper Plants' (Capsicum frutescens L.) Growth and Yield

The primary issue encountered in the cultivation of cayenne pepper is the low production levels attributed to the non-intensive cultivation system and poor soil fertility. Enhancing cultivation techniques, mainly through the application of liquid organic fertilizer derived from Kepok banana humps, has the potential to boost production yields. Kepok banana humps harbor microbes that aid in the decomposition of beneficial organic matter. The objective of this study is to assess the impact and optimal concentration of liquid organic fertilizer from Kepok banana humps on the growth and yield of cayenne pepper. Employing a Completely Randomized Design (CRD) with 4 treatments and 3 replications, the findings indicated that the utilization of liquid organic fertilizer from Kepok banana humps significantly influenced flowering age, harvest age, fruit weight per plant, and plant dry weight. At the same time, no notable effects were observed on plant height and leaf width. The most effective treatment was P3 (300 ml/plant), which yielded the most favorable outcomes across these parameters.

Evaluation of Microbe-Enriched Organic Fertilizer on Three Hybrid Corn (Zea Mays L.) Varieties in Swamp Land

Lowland areas are characterized by poor soil fertility and low nutrient content, making them suboptimal for agriculture. However, these lands have the potential to be developed for agricultural purposes, particularly for cultivating hybrid corn plants. To enhance production, organic fertilizers enriched with Azospirilium microbes and Phosphate Solubilizing Bacteria (BPF) are utilized, along with the planting of superior varieties that are tolerant to lowland conditions. Azospirilium microbes play a crucial role in providing nitrogen (N) nutrients through the nitrogenase enzyme, while BPF contributes phosphorus (P) and potassium (K) nutrients through the phosphatase enzyme. This combination of nutrients is essential for hybrid corn plants to thrive and produce effectively. The research conducted in Pulau Semambu Village, North Inderalaya District, Ogan Ilir Regency, from January to April 2023, employed a field experiment method using a Factorial Randomized Block Design with 9 treatment combinations repeated 3 times. The study involved three varieties (Pioneer 21, Bisi 816, Pertiwi) and three organic fertilizer dosages (100 kg/ha, 300 kg/ha, 500 kg/ha). The highest yield was achieved by applying 300 kg/ha of microbe-enriched organic fertilizer in combination with the Bisi 816 variety, resulting in a yield of 4.24 kg/plot or 5.65 tonnes/ha. This result represented a 60% increase compared to the Pioneer 21 variety treated with 100 kg/ha of microbial-enriched organic fertilizer.

Effect of Biochar on Apple Yield and Quality in Aged Apple Orchards on the Loess Plateau (China)

Apples are not only a foodstuff, but also a raw material for many industrial production fields, and the market demand is constantly increasing. The Loess Plateau is one of the world’s largest apple-producing areas, with about 85% are aged orchards (more than 20 years old), facing problems such as poor soil water retention, degradation of tree strength, and declining yield and quality, etc., so do aged orchards in other regions of the world, and study on improving quality and increasing yield of aged orchards is of great significance to the sustainable development of the apple industry. Here, 6 treatments (2, 4, 6, 8, 10 and 12 kg/plant) were designed in the experiment to study the effects of biochar on yield and quality in aged apple orchards. The study showed that: biochar could improve soil water retention, but caused the soil alkalization; biochar could improve apple quality and increase yield, T3 and T4 were of better quality, and T3 had the highest yield. Comprehensive analysis, T3 is the optimal scheme. The results not only provide a reference for aged orchards worldwide, but also have great significance for the sustainable development of the apple industry.

Farmer perceptions, knowledge, and management of fall armyworm in maize production in Uganda.

Spodoptera frugiperda (J.E. Smith), fall armyworm (FAW), a polyphagous Noctuid pest, was first reported in Uganda in 2016. Farmers were trained to identify and manage the pest, but there was a lack of information on farmer knowledge, perceptions and practices deployed to control it. Therefore, we conducted a survey to assess maize farmers' knowledge, perceptions and management of the pest during the invasion. We interviewed 1,289 maize farmers from 10 maize-growing agro-ecological zones (AEZ) of Uganda using well-structured questionnaires. The data were analyzed using R version 4.2.3. The respondents faced many constraints, including pests, drought, poor soils and labor constraints. Among the pests, FAW was ranked by most (85%) of the respondents as the number one pest problem in maize, and some farmers reported having noticed it way back in 2014. By 2018, more than 90% of the farmers had seen or heard about FAW, and about 80% saw FAW in their fields. The most common FAW symptoms reported by maize farmers were windowing, near tunnel damage, and holes on the cobs. The developmental stages of FAW identified by farmers included eggs (10%), young larvae (78.7%), mature larvae (73.5%) and adult moths (6.7%). Insecticides were the major control tactic, although some farmers used plant extracts, hand-picking, sand, and ash. Farmers sourced information on FAW from various sources, including fellow farmers, radio/TV, extension agents, input dealers, print media, research and NGO extension. There is a need to package clear and uniform information for the farmers and to develop and promote a sustainable solution for FAW management, including harnessing biological control and cultural practices.

Deer grazing drove an assemblage‐level evolution of plant dwarfism in an insular system

Abstract Plant dwarfism, a syndrome characterised by a significant reduction in plant height and organ size, is a widely observed pattern of stress‐tolerant life‐form evolution that results from local adaptation to harsh environmental conditions. The drivers of assemblage‐level dwarfism have primarily been attributed to abiotic factors, such as low temperature, aridity, poor soil fertility or frequent fires. While biotic factors such as grazing pressure from herbivores can contribute to the establishment of plant dwarfism, these factors have rarely been tested at assemblage levels. Focusing on a dwarf plant assemblage comprising over 80 taxa on a small continental island in Japan with a high deer density, we hypothesised that historical deer grazing could also be a factor contributing to the large‐scale convergent evolution of dwarfism. To test this hypothesis, we measured the size of 1908 individual plants of 40 taxa pairs, comprising both palatable and unpalatable pairs from the island and their counterpart taxa from neighbouring regions, and sought to assess which factors (i.e. low solar radiation, estimated divergence time, low nutrient conditions and grazing pressure from deer) may have contributed to the formation of the dwarf plant assemblage on the island. We also performed genetic analysis to infer the time frames for the establishment of dwarf taxa. Statistical analyses revealed that plant size was significantly reduced mainly among the palatable taxa growing on the island, with preferential grazing by deer being identified as the most significant factor influencing plant size. Furthermore, genetic analyses revealed that dwarf ecotypes may have evolved over tens of thousands of years. Synthesis: To the best of our knowledge, this study is the first to demonstrate that interactions with herbivores can shape the assemblage‐level convergence of plant dwarfism. These findings enhance our current understanding of the formation of plant functional diversity.

Eco-Sustainability of Soils in Baby-Leaf Crop Systems under Tunnel through the Application of C-Rich Inputs: Towards Combating Soil Degradation

Fresh-cut leafy vegetables are produced in Southern Italy in very intensive crop systems under tunnel greenhouses in which continuous cropping has triggered soil organic carbon (SOC) depletion and the risk of degradation of soil fertility. A two-year trial of soil organic amendment was carried out on a private farm producing baby-leaf crops on a very poor OC soil (<1%). Biowaste compost, two types of olive pomace composts and buffalo manure were compared to evaluate their ability to recover a positive SOC balance and sustain crop growth and yield. The effects on soil health and crop system were studied by measuring different aspects such as SOC stock change and SOC sequestration rate, soil microbial biomass and nine enzyme activities, yields of rocket and concentration of nitrates in leaves. Soil amendments were distributed once a year at doses of 15 and 30 Mg ha−1 as fresh matter without integration of mineral fertilizers. In our study, the SOC stock improved in the amended soils in a range of 4–6 Mg ha−1, except for dose 30 of buffalo manure, with the highest values where biowaste compost was applied. Our data showed an increase in biological parameters in all the amended soils with respect to Control. In soil amended with olive pomace, however, compost mineralization rates likely did not match crops’ nutrient needs so the yields of rocket were lower than with the biowaste compost and buffalo manure. Biowaste compost showed the best results as it balanced the best C conversion efficiency, the higher increment of SOC and yields of rocket.

Enzyme activities and microbial nutrient limitations in response to digestate and compost additions in organic matter poor soils in the Marches, Italy

Digestate and its derived composts are valuable organic fertilizers for growing vegetables and field crops. However, the impacts on enzymatic activities and microbial resources acquisition pattern are not well addressed. This study investigated ecoenzymatic activities and microbial resource acquisition patterns following these organic fertilizations for sunflower cultivation. The experiment involved applying digestate, five compost types derived from digestate, and inorganic N fertilizer (NINORG), with a control plot having no treatment. Activities of nine enzymes related to C-, N-, P-, and S- acquiring were measured at three development stages: seedling, pre-blooming, and harvest. Across all treatments, resource allocations, especially for C-, N-, and P- acquisitions, increased with plant development, correlating positively with microbial biomass, soil organic carbon, and soil nutrients contents, showing the heightened energy and nutrient sources stimulated microbial growth, prompting increased resource allocation to meet elevated demands, particularly in later crop developmental stages. Stoichiometric analysis revealed greater investments in P compared to N and C, persisting throughout the study period, with P acquisitions at least four-fold greater than N and at least seven times greater than C. This pattern was greatly impacted at harvest for all treatments except NINORG and control, with a reduced investment rate for P- acquisition compared to that of C-, N-, albeit the C: N:P ratio was still far short of the global mean 1:1:1 ratio. The strong negative correlation between available P and vector angle (p<0.001) indicated that the addition of bioavailable P through organic amendments helped reduce the gap towards the ideal ratio. In summary, on soils with imbalanced microbial nutrient and energy demands, organic amendments intensified microbial growth, resulting in heightened nutrient acquisition. However, the declining trend in P acquisition rates compared to C and N over the cropping period suggests possible adjustments with the help of organic fertilizations. Organic fertilizers, by addressing energy-nutrient imbalances, can contribute to a healthier soil ecosystem under conventional farming systems.

Exploring Synergistic Effects of Levan and Levan-Metabolizing Bacillaceae in Promoting Growth and Enhancing Immunity of Tomato and Wheat.

Boosting plant immunity by priming agents can lower agrochemical dependency in plant production. Levan and levan-derived oligosaccharides (LOS) act as priming agents against biotic stress in several crops. Additionally, beneficial microbes can promote plant growth and protect against fungal diseases. This study assessed possible synergistic effects caused by levan, LOS and five levan- and LOS-metabolizing Bacillaceae (Bacillus and Priestia) strains in tomato and wheat. Leaf and seed defense priming assays were conducted in non-soil (semi-sterile substrate) and soil-based systems, focusing on tomato-Botrytis cinerea and wheat-Magnaporthe oryzae Triticum (MoT) pathosystems. In the non-soil system, seed defense priming with levan, the strains (especially Bacillus velezensis GA1), or their combination significantly promoted tomato growth and protection against B. cinerea. While no growth stimulatory effects were observed for wheat, disease protective effects were also observed in the wheat-MoT pathosystem. When grown in soil and subjected to leaf defense priming, tomato plants co-applied with levan and the bacterial strains showed increased resistance to B. cinerea compared with plants treated with levan or single strains, and these effects were synergistic in some cases. For seed defense priming in soil, more synergistic effects on disease tolerance were observed in a non-fertilized soil as compared to a fertilized soil, suggesting that potential prebiotic effects of levan are more prominent in poor soils. The potential of using combinations of Bacilliaceae and levan in sustainable agriculture is discussed.

Pedological features of a sustainable halophyte wetland: El Hito saline pond (Central Spain)

AbstractIn semi‐arid Mediterranean regions, particularly in some wetland soils, salinity is thought to be an indicator of low‐quality soils. In this study, a characterization is presented of the soils surrounding El Hito saline pond (Castilla La Mancha, Central Spain), an ecological halophyte niche within a natural semi‐arid steppe land. The main aim is to classify the salt‐affected soils and their morphology, genesis, and physico‐chemical properties. Four soil profiles were opened with a backhoe machine for sampling and subsequent description on the basis of their pedogenetic morphology. Systematic surface sampling was also performed. Standard methods were followed to measure the soil properties of 27 samples. Overall electrical conductivity (EC) and pH levels of the wetland were mapped (using ArcGIS 3.1.3). Soil salinity at elevated levels was detected, inhibiting plant uptake of water and nutrients. Distinct sub‐areas of extreme elevated surface salinity providing specialized plant habitats and poor soil structure were observed, as well as a mainly whitened‐yellowish‐greenish soil colour due to salt accumulation and poor drainage. The soils also showed alkaline pH values. In most samples, the pH was over 8.5, and EC was higher than 4 (dS m−1), and in several samples higher than 20 (dS m−1). A low sodium (Na) content was detected in the saturation extract where magnesium (Mg+) was the dominant soluble cation, followed by both calcium (Ca+) and sodium (Na+), and then potassium (K+), present in lower proportions. Sulphate (SO42−) and then chloride (Cl−) anions were dominant, although carbon trioxide, (CO3−) and carbonate (CO32−) anions were also present. The percentages of organic carbon (C) were very low, while total nitrogen (TN) and available phosphorus (P) were higher in the upper horizons, suggesting a degree of eutrophication. The present work will increase the existing knowledge about the role of El Hito saline pond, that play a vital ecological role in the broader biosphere, providing new suggestions to readers on how this knowledge can be used to improve these types of ecosystems. In particular, the agricultural pesticides and fertilizers continuously damage the soil fertility as evidenced by the high content of soluble phosphorus found in some points of the Hito saline pond.