Increased Nutrient Availability Research Articles

Enhancing cotton (Gossypium hirsutum L.) productivity and quality with magnetized ionized water and Bacillus subtilis intervention under film-mulched drip irrigation in saline soil in Xinjiang

ContextSoil salinity stress and limited nutrient availability significantly impede crop production. Addressing these challenges, the activation of irrigation water and soil enhancement strategies have proven increasingly effective in improving crop production in saline soils. In particular, magnetized ionized water technology has been shown to augment the leaching of soil salinity, while Bacillus subtilis has been applied to increase nutrient availability. However, information on the synergistic effects of magnetized ionized water and B. subtilis are presently limited. ObjectiveThis study aimed to investigate the potential of utilizing B. subtilis in combination with magnetized ionized water to enhance cotton (Gossypium hirsutum L.) production and understand its underlying driving mechanism. MethodsA two-year field experiment explored the impact of varying amounts of B. subtilis, with two types of irrigation water [non-magnetized-ionized water (NMIW) and magnetized ionized water (MIW)] on soil conditions (pH, salt accumulation, and nutrient content), and cotton growth (dry matter, nutrient accumulation, seed cotton yield, and quality) in southern Xinjiang's saline soil. The experiment included five B. subtilis levels (0, 15, 30, 45, and 60 kg ha−1) with NMIW (designated as B0, B1, B2, B3, and B4) and MIW (designated as MB0, MB1, MB2, MB3, and MB4). ResultsMIW and B. subtilis significantly (p < 0.05) reduced soil pH and salt accumulation, while B. subtilis significantly (p < 0.01) increased soil residual nitrate nitrogen and residual available phosphorus content in the 0–40 cm soil layers compared to B0. Furthermore, a significant increase (p < 0.05) in cotton dry matter, nitrogen, and phosphorus accumulation was observed with both measures compared to B0. Seed cotton yield (Y), water productivity (WP), and fiber quality index (FQI) also showed significant improvements (p < 0.05). Compared with the NMIW treatments, the MIW treatments resulted in an average increase in Y of 5.7%, WP of 3.7%, and FQI of 20.2%. Similarly, B. subtilis treatments, compared to no B. subtilis treatments, led to an average increase in Y by 10.6%, WP by 6.9%, and FQI by 29.1%. Quadratic function relationships with Y, WP, and FQI were established using B. subtilis amount as an independent variable. The appropriate range of B. subtilis amount under MIW treatment, corresponding to 99.5% of the maximum values of Y, WP, and FQI, was determined to be 51.1–56.4 kg ha−1. ConclusionMIW and B. subtilis have been found to increase nutrient accumulation in cotton by reducing 0–40 cm soil salinity and alkalinity and increasing 0–40 cm soil nutrient content, thereby enhancing cotton production. To optimize the cotton cultivation under film-mulched drip irrigation in saline soil of southern Xinjiang, China, it is recommended to apply 51.1–56.4 kg ha−1B. subtilis under MIW.

Current Advances in the Functional Diversity and Mechanisms Underlying Endophyte-Plant Interactions.

Plant phenotype is a complex entity largely controlled by the genotype and various environmental factors. Importantly, co-evolution has allowed plants to coexist with the biotic factors in their surroundings. Recently, plant endophytes as an external plant phenotype, forming part of the complex plethora of the plant microbial assemblage, have gained immense attention from plant scientists. Functionally, endophytes impact the plant in many ways, including increasing nutrient availability, enhancing the ability of plants to cope with both abiotic and biotic stress, and enhancing the accumulation of important plant secondary metabolites. The current state of research has been devoted to evaluating the phenotypic impacts of endophytes on host plants, including their direct influence on plant metabolite accumulation and stress response. However, there is a knowledge gap in how genetic factors influence the interaction of endophytes with host plants, pathogens, and other plant microbial communities, eventually controlling the extended microbial plant phenotype. This review will summarize how host genetic factors can impact the abundance and functional diversity of the endophytic microbial community, how endophytes influence host gene expression, and the host-endophyte-pathogen disease triangle. This information will provide novel insights into how breeders could specifically target the plant-endophyte extended phenotype for crop improvement.

Fast-slow traits predict competition network structure and its response to resources and enemies.

Plants interact in complex networks but how network structure depends on resources, natural enemies and species resource-use strategy remains poorly understood. Here, we quantified competition networks among 18 plants varying in fast-slow strategy, by testing how increased nutrient availability and reduced foliar pathogens affected intra- and inter-specific interactions. Our results show that nitrogen and pathogens altered several aspects of network structure, often in unexpected ways due to fast and slow growing species responding differently. Nitrogen addition increased competition asymmetry in slow growing networks, as expected, but decreased it in fast growing networks. Pathogen reduction made networks more even and less skewed because pathogens targeted weaker competitors. Surprisingly, pathogens and nitrogen dampened each other's effect. Our results show that plant growth strategy is key to understand how competition respond to resources and enemies, a prediction from classic theories which has rarely been tested by linking functional traits to competition networks.

13C Metabolic Flux Analysis in Chondrocytes Reveals a Novel Switch in Metabolic Phenotype.

Chondrocytes are typically known for their anaerobic metabolism both in vivo and under culture conditions in vitro. However, chondrocytes have been shown to display greater biosynthetic activity when subjected to conditions that elicit aerobic metabolism. We have previously shown that tissue formation by chondrocytes can be upregulated by controlling nutrient availability and that this response arises from changes in glucose metabolism. The aim of the present study was to further characterize these changes through 13C-metabolic flux analysis (13C-MFA), as well as to determine the most optimal response. Primary bovine chondrocytes were grown in scaffold-free high-density tissue culture. [U-13C] glucose labeling experiments were combined with a tissue-specific metabolic network model to carry out 13C-MFA under varying levels of nutrient availability. 13C-MFA results demonstrated that when subjected to increasing nutrient availability, chondrocytes switch from a predominately anaerobic to a mixed aerobic-anaerobic phenotype. This metabolic switch was attributed to the saturation of the lactate fermentation pathway and metabolite overflow toward the tricarboxylic acid cycle. This effect appears to be similar to, but the inverse of, the Crabtree effect ("inverse Crabtree effect"). The relationships between metabolic flux and nutrient availability were then utilized to identify culture conditions that promote enhanced tissue formation. This novel metabolic effect presents a simple but effective approach for enhancing the biosynthetic response of chondrocytes-a key requirement to develop functional engineered cartilaginous tissue for joint resurfacing.

Use of Azolla in organic farming on availability and uptake of N, P, K of rice paddy (Oryza Sativa, L.)

Organic fertilization is very important to maintain sustainable land and environmental productivity. Organic fertilizer from Azolla has the advantage of increasing soil fertility by increasing nutrient availability. This study aimed to determine the effect of Azolla application on the availability and uptake of N, P, and K of Inpari 32 variety rice plants. This research used  9 treatments: (T0= control, T1= 90 kg/h NPK, T2= 45 kg/h NPK, T3= 10 t/h Manure, T4= 2 t/h Manure + 90 kg/h NPK, T5= 10 t/h Rice straw compost, T6= 2 t/h Rice straw compost + 90 kg/h NPK, T7= 10 t/h Azolla, T8= 2 t/h Azolla + 90 kg/h NPK) with as control and 3 replications, so there were 27 experimental plots. This research was located in the paddy field of Madiun Regency, East Java. The results showed that Azolla, manure, and straw compost at a dose of 10 t/ha increased soil C-organic, soil Cation Exchange Capacity (CEC), and soil pH, which was still in the neutral range. Azolla fertilizer increased the highest soil total N compared to cow manure and straw compost and increased the efficiency of NPK fertilizer use. Azolla (T7) increased soil available P (27.02 ppm) and exchangeable K (17.63 me/100g soil). Azolla had the highest available P effect. Azolla (T7) and manure (T4) were affected by increasing K-exchange. Azolla fertilizer, manure, and rice straw compost increased vegetative plant growth (plant height, number of tillers, shoot and root biomass). Among the three, Azolla fertilizer had the highest effect. Organic fertilization affected N, P, and K uptake, which was highest in Azola fertilizer (T7). For manure, varied NPK fertilizer (T4) just showed an increase in P uptake, and compost fertilizer varied NPK fertilizer (T6) showed a rise in K uptake. A positive relationship existed between the availability and uptake of nutrients N, P, and K.   

If you can’t beat them, join them: using invasive plants to understand rhizodeposits as drivers of plant-soil feedbacks

The soil microbiome can increase crop resilience to both abiotic and biotic stress, and there is growing interest in uncovering the mechanisms by which we can shape plant associated microbiomes to increase crop yields within stressful environments. Through rhizodeposits, plants influence the composition of microbial communities and abiotic conditions in the rhizosphere, potentially generating plant-soil feedbacks which can increase nutrient availability and competitive ability against neighboring plants. Invasive plants have repeatedly been shown to drive plant-soil feedbacks that increase their ability to adapt to a wide range of environmental conditions and suppress neighboring plants. Using invasive plants as model species, we discuss what is currently known about the mechanisms that generate the plant-soil feedbacks that increase plant productivity, competitive ability, and resilience. Specifically, invasive potential is enhanced through 1) positive direct feedback loops which occur within a species, and can occur through enhanced mutualistic associations; or 2) negative indirect feedback loops, when feedbacks affect heterospecific plants through either allelopathy, disruption of mutualistic associations, and increased pathogen abundance. Knowledge on invasive plant exudate-microbe interactions may increase cropping system resilience through breeding superior crop genotypes, or potentially through soil amendments that disrupt weed-microbe interactions. We argue that because the soil biotic and native plant community often evolve in response to negative indirect feedback loops, focusing breeding efforts on positive direct plant-soil feedbacks, such as those that increase mutualistic associations and nutrient availability in the rhizosphere, are likely to lead to long-term stress resilient crops. Future research should explore to what extent upregulating production of specific exudates in non-invasive crop species generate the same plant-soil feedbacks responsible for invasive plant success.

Production and Analysis of Physical, Chemical and Physico-chemical Properties of Biochar from Various Feed Stock Sources

Biochar was derived from a range of biomass materials and its physical and physicochemical characteristics were assessed. Due to the pyrolysis of various biomass products, such as grass, cotton stalks, coconut husk, coconut shell, paddy straw, rice husk, Eichhornia, sugarcane bagasse, and neem wood in the pyrolysis unit. The biochars' characteristics were extremely diverse. Prosopis is superior to other biochars in terms of pore space, pH, EC, CEC, organic C, total N, Mg, available nutrients, and carbon fractions, as evidenced by the large amount of biochar that was recovered from it.&#x0D; Prosopis wood biochar, which can function as a soil enhancer and improve the physical properties of the soil, is superior than cotton stalk biochar and drymatter biomass biochars. It can also increase nutrient availability and retention. Given its higher recovery and diffusion, Prosopis' resource can be used. As a result of the substantial differences between the various biomass, characterizing biochar made from each one is necessary before mass producing it for agricultural application.

Canopy gap impacts on soil organic carbon and nutrient dynamic: a meta-analysis

Key messageThe forest canopy gaps, formed by natural or anthropogenic factors, have been found to reduce soil carbon content and increase nutrient availability. The magnitudes of these effects have been observed to increase with gap age and size, and are largely influenced by changes in temperature, precipitation, and solar radiation.ContextLocal studies have illustrated the influence of canopy gaps on the spatial heterogeneity of soil carbon and nutrients, playing a pivotal role in driving forest regeneration and succession. Nevertheless, it remains largely unknown whether the response of soil carbon and nutrient content to gap formation is consistent across forest ecosystems at global scale.AimsThe aim of this paper is to assess the homogeneity of the observed responses of soil carbon and nutrients following gap formation among a wide array of forest ecosystems and climatic regions.MethodsWe performed a meta-analysis synthesizing 2127 pairwise observations from 52 published articles to quantify the changes in in soil physical, chemical, and microbial variables resulting from gap creation in natural forests and plantations spanning tropical to boreal regions.ResultsCanopy gaps resulted in significant decrease of soil organic carbon (Corg) and microbial carbon (Cmic). The concentrations of ammonium (NH4+), nitrate (NO3−), and available phosphorus (available P) increased following gap creation. These changes mainly occurred in the growing season and in the mineral soil layer, becoming more pronounced with increasing gap age and size. The change in Corg was negatively regulated by mean annual precipitation, and was associated with the changes in Nt and Nmic. The change in NH4+ was positively regulated by mean annual temperature, and was associated with the changes in available P and oxidoreductases (Ox-EEAs). The model explaining the change in soil carbon content exhibited a higher explanatory power than the one accounting for changes in soil nutrient availability.ConclusionThe results indicated that forest canopy gaps resulted in a reduction in soil carbon content and an increase in nutrient availability. These findings contribute to a better understanding of the role of small-scale disturbances as drivers of forest ecosystem succession.

Improved microalgae growth and lipid production in anaerobic digestate with ultraviolet radiation pretreatment

Inappropriate sterilization strategies inhibit microalgal growth when culturing microalgae with anaerobic digestate. This study aimed to scientifically select a low-cost disinfection pretreatment of anaerobic digestate for large-scale microalgae cultivations. In this work, three different methods, including autoclaving, ultraviolet or NaClO treatments, were employed to sterilize the municipal anaerobic digestate. Scenedesmus quadricauda was then cultured in diluted liquid digestate for the simultaneous lipid production and nutrient removal. The results indicated that the growth of S. quadricauda was inhibited after NaClO treatment due to the residual free chlorine. The 15-min ultraviolet effectively mitigated microbial contamination and increasing nutrient availability, enhancing the electron transport of microalgal photosynthesis. After 6-days cultivation, the microalgal biomass concentration of the ultraviolet group was 1.09 g/L, comparable to that of the autoclaving group (1.15 g/L). High nutrient removal efficiency was observed: COD (93.30 %), NH4+-N (92.56 %), TN (85.82 %) and TP (95.12 %). Moreover, S. quadricauda outcompeted the indigenous microorganisms, contributing to its dominance in the culture system of ultraviolet group. The facultative anaerobe Comamonadaceae and aerobes Moraxellaceae, rather than strict anaerobe Paludibacteraceae and Bacteroidetes_vadinHA17, played vital roles in synergistic removal of contaminants by bacteria and algae. The potential competition for nitrogen and phosphorus by bacteria contributed to the ultraviolet group having the greatest lipid content (48.19 %). Therefore, this work suggested using 15-min ultraviolet treatment for anaerobic digestate in large-scale microalgae cultivation.

Impact of harmful algal bloom severity on bacterial communities in a full-scale biological filtration system for drinking water treatment

The occurrence of harmful algal blooms (HABs) in freshwater environments has been expanded worldwide with growing frequency and severity. HABs can pose a threat to public water supplies, raising concerns about safety of treated water. Many studies have provided valuable information about the impacts of HABs and management strategies on the early-stage treatment processes (e.g., pre-oxidation and coagulation/flocculation) in conventional drinking water treatment plants (DWTPs). However, the potential effect of HAB-impacted water in the granular media filtration has not been well studied. Biologically-active filters (BAFs), which are used in drinking water treatment and rely largely on bacterial community interactions, have not been examined during HABs in full-scale DWTPs. In this study, we assessed the bacterial community structure of BAFs, functional profiles, assembly processes, and bio-interactions in the community during both severe and mild HABs. Our findings indicate that bacterial diversity in BAFs significantly decreases during severe HABs due to the predominance of bloom-associated bacteria (e.g., Spingopyxis, Porphyrobacter, and Sphingomonas). The excitation-emission matrix combined with parallel factor analysis (EEM-PARAFAC) confirmed that filter influent affected by the severe HAB contained a higher portion of protein-like substances than filter influent samples during a mild bloom. In addition, BAF community functions showed increases in metabolisms associated with intracellular algal organic matter (AOM), such as lipids and amino acids, during severe HABs. Further ecological process and network analyses revealed that severe HAB, accompanied by the abundance of bloom-associated taxa and increased nutrient availability, led to not only strong stochastic processes in the assembly process, but also a bacterial community with lower complexity in BAFs. Overall, this study provides deeper insights into BAF bacterial community structure, function, and assembly in response to HABs.

Identifying biochar production variables to maximise exchangeable cations and increase nutrient availability in soils

Biochar is a product of the thermal treatment of sustainably sourced organics or waste biomass, which enhances nutrient availability and exchangeable cations after soil application. Biochar feedstock is one of the primary factors influencing the availability of exchangeable cations in biochar and soil-biochar mix. However, this influence is not satisfactorily understood due to contrasting data among literature for the cation exchange capacity (CEC) and the lack of standard analysis methods for CEC of biochar and soil-biochar mixtures. Therefore, this research was conducted to assess cation exchange in contrasting soil-biochar mixes, where CEC is measured as (1) the sum of base cations (Na+, K+, Mg 2+, and Ca2+) displaced by ammonium acetate (CEC-BC) and (2) NH4+ displaced by potassium chloride (CEC-NH4+). For the first time, we have evaluated CEC-BC and CEC-NH4+ in 21 different biochar samples using a modified method. We then used 12 representative biochars with 3 soil types (2% w/w biochar) and provided insights on relative changes in CEC-BC and individual base cations. Some previous studies have indicated a relationship between CEC and surface area and a degree of additivity in the resulting CEC of soil-biochar mixes. However, our study demonstrates an absence of these correlations and a lack of additivity in the representative biochar products. We found that biochar prepared from mixed garden wastes can increase K+ or Ca2+ in loamy or sandy soils and mitigate potential soil sodicity problems in loamy soils. However, a clayey soil may or may not need biochar for the specific purpose of increasing exchangeable cations. Our results revealed that biochar prepared from hardwood or mixed garden waste can retain NH4+ and deliver it to soil acting as a sink and source for soil nutrients.

Population-level responses of aphids to pulsed drought stress

AbstractThe first aim of this study was to test the pulsed stress hypothesis on a system consisting of young spring wheat (Triticum aestivum L.) and the rose-grain aphid Metopolophium dirhodum (Walker) by following the age-stage, two-sex life table theory. This hypothesis predicts that fluid-feeding insects benefit from feeding on plants intermittently stressed by drought due to the increased nutrient availability and restored cell turgor. Our second aim was to illustrate the risk of drawing different conclusions if based on a single or a small subset of parameters or if the entire lifespan of a generation is not covered compared to if the study was conducted at the population level. We applied periods of drought stress (soil water capacity, SWC = 40%) on four occasions relative to the population development of the aphids and compared those treatments with well-watered (SWC = 70%) and continuous stress conditions (SWC = 40%). The timing of the stresses appeared to be important in determining the effect on aphid performance. Although we found some improvement in fecundity when the stress occurred before the aphids were placed on the plants, the overall effect of the early-timed pulsed stress treatments on the rate of increase was negative compared to the well-watered control, which was mainly due to prolonged nymph development. The drought pulse that was timed late (the second week of aphid reproduction) did not show any effect relative to the well-watered control. This study therefore provides no clear support for the validity of the pulsed stress hypothesis.

Humic and Fulvic Acids Promote Growth and Flowering in Petunias at Low and Optimal Fertility

Humic substances are components of soil organic matter that influence soil structure and fertility. Humic and fulvic acids can be extracted from soil and other organic sources, and are used as biostimulants to promote plant growth and increase nutrient availability and uptake. The goal of this study was to determine whether selected humic and fulvic acid–based commercial products would promote growth and flowering of petunia (Petunia ×hybrida) ‘Picobella Blue’ grown in soilless media with low or optimal fertilizer rates. Plants were grown in 11.4-cm pots filled with peat-based media [80:20 peat:perlite (v/v); pH 5.4]. Three biostimulant products were evaluated at different rates and application frequencies: Huma Pro, a liquid humic acid biostimulant; Fulvi Pro, a liquid fulvic acid biostimulant; and Micromate, a powder containing both humic and fulvic acids. In Expt. 1, Huma Pro and Fulvi Pro were drenched weekly onto the growing media at a rate of 5, 10, or 20 mL⋅L–1; Micromate was drenched weekly at a rate of 5, 10, 20, or 40 g⋅L–1. Plants were fertilized with either 50 mg⋅L–1 nitrogen (N) (low fertility) or 100 mg⋅L–1 N (optimal fertility) from Jack’s Professional 20N–1.3P–15.7K Petunia FeED each irrigation. Control plants received fertilizer but no biostimulant treatments. In Expt. 2, biostimulant treatments were drenched once at transplant, biweekly, or weekly at a rate of 1.25, 2.5, 5, or 10 mL⋅L–1 for Huma Pro and Fulvi Pro; and at 5, 10, 20, or 40 g⋅L–1 for Micromate. All plants received constant liquid feed at the lower fertilizer rate of 50 mg⋅L–1 N. In Expt. 1, plants fertilized with 100 mg⋅L–1 N and treated with 20 g⋅L–1 Micromate had the best performance. The average shoot dry weight was 32% greater than that of the control plants. Micromate (20 g⋅L–1)-treated plants had an average of five more flowers per plant, and they flowered 4 days earlier than untreated control plants. In Expt. 2, plants treated with 40 g⋅L–1 of Micromate weekly had the greatest shoot dry weight compared with the other treatments. Weekly Micromate treatments (40 g⋅L–1) resulted in plants with an average of 13 more flowers per plant, which flowered 7 days earlier than control plants. Plants treated with Fulvi Pro and Huma Pro at 20 mL⋅L–1 had a significantly greater concentration of potassium in shoot tissue, whereas Micromate treatments at 20 and 40 g⋅L–1 resulted in a greater concentration of phosphorous in the shoots. The humic and fulvic acids in Micromate improved petunia crop quality by promoting vegetative growth, increasing flower numbers, and reducing the time to flower.

Effect of Beneficial Microbes on Macronutrient Uptake and Oil Palm Seedling Growth in Peat Soil

Peat soil has low fertility due to low content of macronutrients, such as N, P, K, Ca, & Mg. Efforts that can be made to increase nutrient availability and nutrient uptake for plants on peatlands are the utilization of beneficial microbes such as endophytic bacteria and arbuscular mycorrhizae. This study aims to identify the role of endophytic bacteria and arbuscular mycorrhizae applied to peat soil media to help increase macronutrient uptake and the growth of oil palm seedlings (main nursery). This study was conducted in June – December 2022. The peat soil sample was collected from oil palm plantations located in Siak Regency, Riau, with coordinates 0°45′22″ N, 101°44′27″ E. The experimental design used in this study was a completely randomized design (CRD) with 8 treatments and 5 replicates. The treatment given in this study was a variation of beneficial microbes with zeolite as the carrier. Beneficial microbes used in this study were arbuscular mycorrhizae, namely Glomus sp, and endophytic bacteria, i.e. Burkholderia cenocepacia and Pseudomonas fluorescens. Parameters observed in this study were plant growth (every 1 month) and leaf nutrient (6 months after planted). The results of this study indicated that the consortium application of endophytic bacteria and arbuscular mycorrhizae was the best treatment which was shown to have the best growth of oil palm seedlings compared to all treatments with plant height increment of 55.5 cm; stem diameter increment of 34.3 mm; and the number of fronds addition as many as 11 fronds. This is also supported by macronutrients content in the leaves of oil palm seedlings such as N, P, and K.

Stone milling conditions and starter culture source influence phytic acid content and antioxidant activity in whole‐grain sourdough bread

AbstractBackground and ObjectivesThere is interest in whole‐grain sourdough bread related to evidence of increased nutrient availability and antioxidant compounds. Antioxidants play a remarkable role in the body's defense system against reactive oxygen species. In contrast, phytic acid has adverse effects as it reduces the availability of minerals. This research study was carried out to compare the phytic acid content and antioxidant activity of stone‐milled whole‐grain flour and sourdough bread made with two different starter cultures.FindingsThe phytic acid content of all the bread samples was significantly (p &lt; .05) lower than the flour samples they were produced from. Significant (p &lt; .05) differences were observed in sourdoughs' phenolic contents and antioxidant capacities with different starter cultures. The antioxidant capacity of polyphenols extracted from bread samples was negatively correlated with the coarse particle size fraction and positively correlated with the fine particle size fraction.ConclusionsThe phytic acid content and antioxidant capacity of the bread were affected by the starter culture. Processing whole‐grain flour into sourdough bread reduced the phytic acid content and improved the antioxidant activity.Significance and NoveltyThe content of bioactive compounds and anti‐nutritional factors in sourdough bread can be monitored by using different milling conditions, particle sizes, and starter cultures.

Influence of Vinasse and Mechanized Harvesting on the Physical and Chemical Aspects of Soil in Paudalho Municipality - PE

Sugarcane cultivation methods and processes usually have negative impacts on the environment. However, this industry has been seeking more sustainable technologies, ranging from the adequate disposal of the organic residues produced to the elimination of pre-harvest burning and introduction of mechanized harvest. The objective of this work was to verify the influence of vinasse application and mechanized harvesting on the physical and chemical aspects of a dystrophic Red Yellow Argisol of medium texture, cultivated with sugarcane. For this, a field experiment in a Completely Randomized Design, with a factorial scheme was conducted. Four management treatments, with three replications, were evaluated: T1 - Without application of vinasse, burned cane followed by manual harvest, without irrigation; T2 - With application of vinasse, mechanized harvest, without irrigation; T3 - With application of vinasse, mechanized harvest, with irrigation; T4 - With application of vinasse, burned cane followed by manual harvest, without irrigation. Soil samples were collected in three depths (0 – 20 cm, 20 – 40 cm and 40 – 60 cm) and soil physical and chemical characteristics were determined. The data obtained were submitted to ANOVA and compared by the Tukey test (p≤0.05) of probability, using the statistical program ASSISTAT 7.7 beta. The results showed that fertigation with vinasse did not influence soil density, particle density, and total porosity. However, mechanized harvesting increased soil density and total porosity. The soil in the experimental unit without vinasse application presented a more acidic pH and high levels of aluminum saturation, causing a decrease in the availability of nutrients, and the soils treated with vinasse had an increase in nutrient availability. Therefore, the addition of vinasse can be an important strategy in maintaining and increasing long-term soil fertility in sugarcane cropping systems.

Pengelolaan Daun Kering untuk Pupuk Kompos

A material given to plants to increase nutrient availability is called fertilizer. This research project aims to find a solution to the environmental pollution problem caused by the accumulation of dry leaf litter. Compost is made using dry leaf litter waste as the main component and EM4 as an aid. EM4 is responsible for breaking down the organic material in the leaves. The finished dry leaf compost is odorless, in the form of loose granules, has a brittle and somewhat rough texture, and is dark brown in color. The research method used is literature research, or research derived from books and print journals accessible on Google Scholar. This type of research uses descriptive studies and several works of researchers with relevant fields of study. Data collected through inductive methods are then analyzed using one or more initial data sets. The obtained data is examined using a descriptive analytical approach. By transforming dry leaves into more useful and economically valuable compost, this research also aims to develop and enhance the creative abilities of the community and the local economy. Bright colors indicate composting that is too dry or moisture levels below 30%. One determining factor of compost maturity is its aroma. The compost fermentation process will produce various strong aromas.

Predation and Biophysical Context Control Long-Term Carcass Nutrient Inputs in an Andean Ecosystem

Animal carcass decomposition is an often-overlooked component of nutrient cycles. The importance of carcass decomposition for increasing nutrient availability has been demonstrated in several ecosystems, but impacts in arid lands are poorly understood. In a protected high desert landscape in Argentina, puma predation of vicuñas is a main driver of carcass distribution. Here, we sampled puma kill sites across three habitats (plains, canyons, and meadows) to evaluate the impacts of vicuña carcass and stomach decomposition on soil and plant nutrients up to 5 years after carcass deposition. Soil beneath both carcasses and stomachs had significantly higher soil nutrient content than adjacent reference sites in arid, nutrient-poor plains and canyons, but not in moist, nutrient-rich meadows. Stomachs had greater effects on soil nutrients than carcasses. However, we did not detect higher plant N concentrations at kill sites. The biogeochemical effects of puma kills persisted for several years and increased over time, indicating that kills do not create ephemeral nutrient pulses, but can have lasting effects on the distribution of soil nutrients. Comparison to broader spatial patterns of predation risk reveals that puma predation of vicuñas is more likely in nutrient-rich sites, but carcasses have the greatest effects on soil nutrients in nutrient-poor environments, such that carcasses increase localized heterogeneity by generating nutrient hotspots in less productive environments. Predation and carcass decomposition may thus be important overlooked factors influencing ecosystem functioning in arid environments.

High nutrient availability modulates photosynthetic performance and biochemical components of the economically important marine macroalga Kappaphycus alvarezii (Rhodophyta) in response to ocean acidification

Increased atmospheric CO2 concentrations not only change the components of inorganic carbon system in seawater, resulting in ocean acidification, but also lead to decreased seawater pH, resulting in ocean acidification. Consequently, increased inorganic carbon concentrations in seawater provide a sufficient carbon source for macroalgal photosynthesis and growth. Increased domestic sewage and industrial wastewater discharge into coastal areas has led to nutrient accumulation in coastal seawaters. Combined with elevated pCO2 (1200 ppmv), increased nutrient availability always stimulates the growth of non-calcifying macroalgae, such as red economical macroalga Gracilariopsis lemaneiformis. Here, we evaluated the interactive effects of nutrients with elevated pCO2 on the economically important marine macroalga Kappaphycus alvarezii (Rhodophyta) in a factorial 21-day coupling experiment. The effects of increased nutrient availability on photosynthesis and photosynthetic pigments of K. alvarezii were greater than those of pCO2 concentration. The highest Fv/Fm values (0.660 ± 0.019 and 0.666 ± 0.030, respectively) were obtained at 2 μmol L−1 of NO3–N at two pCO2 levels. Under the elevated pCO2 condition, the Chl-a content was lowest (0.007 ± 0.004 mg g−1) at 2 μmol L−1 of NO3–N and highest (0.024 ± 0.002 mg g−1) at 50 μmol L−1 of NO3–N. The phycocyanin content was highest (0.052 ± 0.012 mg g−1) at 150 μmol L−1 of NO3–N under elevated pCO2 condition. The malondialdehyde content declined from 32.025 ± 4.558 nmol g−1 to 26.660 ± 3.124 nmol g−1 with the increased nutrients at under low pCO2. To modulate suitable adjustments, soluble biochemical components such as soluble carbohydrate, soluble protein, free amino acids, and proline were abundantly secreted and were likely to protect the integrity of cellular structures under elevated nutrient availability. Our findings can serve as a reference for cultivation and bioremediation methods under future environmental conditions.

Short-term continuous monocropping reduces peanut yield mainly via altering soil enzyme activity and fungal community

Continuous monocropping can lead to soil sickness and increase of soil-borne disease, which finally reduces crop yield. Microorganisms benefit plants by increasing nutrient availability, participating in auxin synthesis, and defending against pathogens. However, little is known about the influence of short-term successive peanuts cropping on soil properties, enzyme activities, its yield, plant-associated microbes, and their potential correlations in peanut production. Here, we examined the community structure, composition, network structure and function of microbes in the rhizosphere and bulk soils under different monocropping years. Moreover, we assessed the impact of changes in the soil micro-environment and associated soil microbes on peanut yield. Our results showed that increase of monocropping year significantly decreased most soil properties, enzyme activities and peanut yield (p < 0.05). Principal co-ordinates analysis (PCoA) and analysis of similarities (ANOSIM) indicated that monocropping year significantly influenced the fungal community structure in the rhizosphere and bulk soils (p < 0.01), while had no effect on the bacterial community. With the increase of continuous monocropping year, peanut selectively decreased (e.g., Candidatus_Entotheonella, Bacillus and Bryobacter) or increased (e.g., Nitrospira, Nocardioides, Ensifer, Gaiella, and Novosphingobium) the abundance of some beneficial bacterial genera in the rhizosphere. Continuous monocropping significantly increased the abundance of plant pathogens (e.g., Plectosphaerella, Colletotrichum, Lectera, Gibberella, Metarhizium, and Microdochium) in the rhizosphere and negatively affected the balance of fungal community. Besides, these species were correlated negatively with L-leucine aminopeptidase (LAP) activity. Network co-occurrence analysis showed that continuous monocropping simplified the interaction network of bacteria and fungi. Random forest and partial least squares path modeling (PLS-PM) analysis further showed that fungal community, pathogen abundance, soil pH, and LAP activity negatively affected peanut yield. In conclusion, short-term continuous monocropping decreased LAP activity and increased potential fungal pathogens abundance, leading to reduction of peanut yield.