Manure Application Research Articles

The Role of Organic Amendments and Their Impact on Soil Restoration: A Review

Soil organic matter (SOM) plays a pivotal role in maintaining soil health by enhancing its physical, chemical, and biological properties. It improves soil structure, water retention, nutrient availability, and microbial activity, contributing significantly to sustainable agriculture. Organic amendments, including animal manure, compost, biosolids, crop residues, and various organic by-products, are widely used to restore degraded soils by increasing SOM content. These amendments not only supply essential nutrients but also promote biological aggregation, suppress soil-borne pathogens, and improve soil's resistance to environmental stressors such as drought and heavy metal toxicity. The positive impacts of organic amendments on soil properties are well-documented, with key benefits including increased soil organic carbon (SOC), improved nutrient cycling, enhanced microbial diversity, and greater water-holding capacity. Organic materials such as compost and animal manure have been shown to significantly improve soil fertility and restore degraded soils. The application of green manure and crop residues also boosts soil biodiversity, enhances rhizospheric processes, and supports overall ecosystem resilience. This paper emphasizes the importance of adopting holistic soil management practices that include organic amendments, conservation tillage, and sustainable cropping systems to address soil degradation. By focusing on replenishing SOM, improving nutrient availability, and increasing soil biodiversity, these practices can contribute to the long-term sustainability of agricultural systems and environmental health. The restoration of soil organic matter is essential for enhancing soil quality and mitigating degradation, ultimately ensuring food security and ecosystem stability for future generations.

Influence of organic manures on yield parameters of guava (Psidium guajava) cv. Lucknow 49

The present investigation on “Influence of organic manures on yield parameters of guava (Psidium guajava) cv. Lucknow 49” was conducted in a farmer’s field located at Suthamalli village under Ariyalur District, Tamil Nadu during 2023-24. The study aimed to evaluate the application of organic manures, specifically combinations of farmyard manure, vermicompost, poultry manure, and neem cake significantly enhanced the yield parameters of guava cv. Lucknow 49 compared to untreated control conditions. The field experiment was laid out in randomized block design in three replications with fourteen treatments. The treatments were designed by combination of FYM, vermicompost, poultry manure and neem cake at different levels. The results of the present study indicated that the yield parameters viz., number of flowers/tree (162.16 and 173.36), number of fruits/tree (151.97 and 163.52), fruit set percentage (93.71 % and 94.32%), fruit length (6.71 and 6.98 cm), fruit diameter (6.89 and 7.10 cm), fruit weight (189.22 and 193.27 g) and yield/tree (29.83 and 34.18 kg) was found to be the highest in two successive crops, the treatment which received soil application of FYM 10 kg + vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree followed by vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree. The least values for all the yield parameters were noticed in the untreated control.

Exploring the effect of fertilizer application on yield and decoding CO2 flux under flooded paddy conditions towards sustainable agriculture

The impact of organic and inorganic nutrient management on the emission of carbon dioxide (CO2), soil properties such as available nutrients, microbial population and soil organic carbon (SOC) were investigated in paddy (Oryza sativa L.) field (at 8o 46’ N Latitude and 77o 42?’ E Longitude) under flooded condition during late pishanam season in 2023-2024. The treatments were designed to observe the effects of applying fertilizer based on the soil test crop response (100 % STCR-based NPK) that had been modified by organic amendments, which include absolute control (unfertilized), inorganic fertilizers, sole application of organic amendments (Farm yard manure, Green leaf manure, Vermicompost and Poultry manure) and combined these organic amendments with inorganic fertilizers. The main objective of this study is to understand the intricate relationship between fertilizers and carbon flux in paddy soils, which is crucial for developing sustainable agricultural practices that minimize environmental harm while ensuring food security. The observation of the experimental field study reported that the combined application of poultry manure at the rate of 5 tonnes per hectare with 100% STCR-based inorganic fertilizer recorded maximum yield and yield attributes. The treatment combination of poultry manure + inorganic fertilizer enhanced in sequestrating the soil organic carbon (0.67%) resulted in higher grain yield (5972 kg ha-1) and also observed that this combination will limit the emission of CO2 to the atmosphere. Therefore, it could be a better choice for carbon storage and higher productivity in a sustainable rice cropping system.

The Response of Inorganic and Organic Fertilizers on Growth, Yield and Quality of Cluster Bean [Cyamopsis tetragonoloba (L.) Taub.] in the Village Chikkenahalli of Challakere Taluk, Chitraduraga District

Cluster bean is one of the significant yet underutilized leguminous vegetables belonging to family fabaceae. It is known by various names across the country such as gaur, chavli kaayi, gori kaayi, khutt, govar, and kothavare. A field experiment on cluster bean was carried out during the summer season of the year 2024 at the farm of P. L. Dodda Rangegowda in Chikkenahalli of Challakere taluk, Chitradurga district, Karnataka. The primary objectives of the study are to examine the effects of organic and inorganic fertilizers on the productivity and growth characteristics of cluster bean; to identify the advantages and disadvantages of these fertilizers in relation to productivity, soil fertility, and environment and further to review the effects of mixed organic and inorganic fertilizers on yield and soil fertility. The experiment was laid out in a randomized block design with four replications and five treatments which comprised of 100 percent organic (FYM and chicken manure), 100 percent inorganic (NPK), 50 percent organic + 50 percent inorganic, 100 percent organic + jeevamruta and control. The results revealed that, treatment T3 outperformed the others, showing the highest values for plant height, number of branches per plant, days to first flowering, days to first vegetable harvest, pod length, pod width, yield per plant, yield per plot, and yield per hectare, while the control recorded the lowest values. Soil properties such as pH, EC, SOC and NPK levels improved when combination of organic and inorganic fertilizers were applied together. Based on these results, it can be concluded that, the application of organic manures, along with chemical fertilizers, positively enhanced the vegetative growth, reproductive growth, yield, quality of cluster bean and soil parameters.

Long-term application of manure increased soil amino acid pool under maize-maize-soybean rotation system

Long-term application of manure increased soil amino acid pool under maize-maize-soybean rotation system

The LTAR Cropland Common Experiment at Platte River/High Plains Aquifer.

The Platte River/High Plains Aquifer (PR/HPA) region is characterized by cropland, pastures, and grasslands that are faced with changing climatic conditions and agricultural intensification. The PR/HPA Long-Term Agroecosystem Research (LTAR) site is located in Eastern Nebraska with the goal of improving resilience, sustainability, and profitability of agroecosystems through enhancing ecosystem services and environmental quality, developing strategies for efficient agricultural production, and mitigating and adapting to climate change. To meet this goal, a common experiment and five ancillary experiments have been developed to evaluate prevailing regional practices in grain crop production systems compared to alternative practices in rainfed and irrigated systems. These experiments reflect different geographic regions and cropping systems within PR/HPA. The common experiment is at a plot scale under sub-drip irrigation. The prevailing practice is a corn-soybean rotation with a fixed N fertilizer rate. The alternative practice is a corn-winter wheat-relay cropped soybean rotation with temporally variable N rates using fertigation. There is also an auxiliary alternative practice, a corn-soybean rotation with temporally variable N rates using fertigation with fall manure application after soybean harvest. This document describes the regional characteristics, cropland LTAR experiments, stakeholder engagement, and future plans for the PR/HPA cropland experiments.

Long-term effects of agronomic practices on winter wheat yield and NUE in dryland regions of USA and China: a long-term meta-analysis

Dryland agriculture is fundamental to global crop production and vital to food security. Conservation tillage is extensively practiced in USA wheat cultivation. Meanwhile, the adoption of conservation tillage by Chinese farmers is limited. This meta-analysis compared the yield and nitrogen use efficiency (NUE) between conservation tillage and conventional tillage (CT) with different types of cropping systems, mulching methods, levels of nitrogen fertilizer (NF), and addition of manure. The meta-analysis presented that conservation tillage at high-NF enhanced the yield and NUE, and reduced the yield and NUE at low-NF, compared to CT. The interaction of conservation tillage with leguminous cover crops (LCC) and manure application increased the yield and NUE at low-NF, compared to CT. Non-leguminous cover crops (NLCC) increased the yield and NUE under high-NF than low-NF. The interaction of conservation tillage with management practices showed that the no-tillage (NT) with leguminous cover crops (LCC) significantly increased wheat yield by 58% and NUE by 47% under low-NF compared to CT. However, increasing the rate of NF did not increase the yield under such interaction. Cropping systems, mulching types, and manure application mainly determined the effects of conservation tillage on wheat yield and NUE. The adverse impact of CT on yield and NUE could be alleviated with the application of LCC and manure under moderate NF. We demonstrate that adding LCC and manure have a generally substitutive relationship with N fertilizer, resulting in a significant increase in wheat yield and NUE at low-NF doses as at high N fertilizer dosages. Therefore, based on the obtained results, moderate NF with LCC and manure application is recommended for growing winter wheat in dryland regions of the USA and China.

Synergistic Promotion of Particulate and Mineral-Associated Organic Carbon Within Soil Aggregates After 10 Years of Organic Fertilization in Wheat-Maize Systems

How different fertilization practices modify soil organic carbon (SOC) sequestration is still unclear. Our study aimed to evaluate the changes in SOC stocks and their physical fractions after 10 years of organic and inorganic fertilization. Five treatments were established under a wheat-maize system in Northern China: control (CK), chemical fertilizer (F), straw plus chemical fertilizer (SF), manure plus chemical fertilizer (MF), and straw and manure plus chemical fertilizer (SMF). The results showed that the SOC sequestration rate at 0–20 cm depth decreased in the following order: SMF (1.36 Mg C/ha/yr) > MF (1.13 Mg C/ha/yr) > SF (0.72 C/ha/yr) > F (0.15 Mg C/ha/yr) > CK (−0.25 Mg C/ha/yr). The values indicated that straw returning and manure application were important measures to achieve the “4 per 1000” target, and the application of manure was a more effective strategy. The high input of chemical fertilizer only maintained the initial SOC level and was not a powerful C-farming practice. A minimum input of 4.93 Mg C/ha/yr was required to keep the initial SOC storage. The SOC associated with small macroaggregate (0.25–2 mm) was the most sensitive indicator for the changes of bulk SOC. In addition, the accumulation of SOC under SMF, MF, and SF treatments mainly occurred in the occluded particulate organic C (oPOC) in small macroaggregates, indicating that the physical protection of macroaggregates played a predominant role in SOC sequestration. The SMF, MF, and SF treatments also displayed higher mineral organic C (mSOC) in soil aggregates than the CK and F treatments. A transformation of oPOC towards the mSOC fraction indicated that exogenous C further shifted into stable C pools under the physical protection of soil aggregates. In conclusion, these findings confirmed the important role of straw returning and manure application in SOC accumulation and stabilization, highlighting that a combination strategy of straw + manure + chemical fertilizer had the best effect.

Optimizing Lemon Balm (Melissa Officinalis L.) Cultivation: Effects of Different Manures on Plant Growth and Essential Oil Production During Consecutive Harvests

This study examined the impact of organic manures from different sources (poultry, sheep, and cattle) on lemon balm (Melissa officinalis L., Lamiaceae) during different harvests. Manure application increased the photosynthetic pigments levels (chlorophyll-a, 9–41%; chlorophyll-b, 24–60%), biomass (41–60%), and essential oil yield (60–71%). Sheep manure treatment exhibited the highest antioxidant capacity among all the manures tested. Through GC-MS and GC-FID analysis, 10 chemical constituents were identified in the essential oil, accounting together for 91–95% of the total composition. The primary chemical component was geranial (39–46%), followed by neral (28–35%), (E)-caryophyllene (4.7–11%), geranyl acetate (2.7–5.9%), and caryophyllene oxide (1.7–4.8%). The utilization of livestock manures significantly improved the quality of the essential oil in terms of neral and geranial percentages compared to the control. Notably, during mid-August and early October, there was a substantial rise in these valuable compounds. However, a decrease in geranyl acetate and oxygenated monoterpenes resulted in a decline of the antioxidant capacity to 3%. Consequently, it is recommended to utilize essential oils from the second and third harvests for industrial purposes. Overall, the use of livestock manures, especially sheep manure, as a nutrient source for lemon balm cultivation, proves to be a viable approach for producing high-quality essential oils.

Investigating the Synergistic Effect of Tillage System and Manure Application Rates on Selected Properties of Two Soil Types in Limpopo Province, South Africa

Sustainable agricultural practices are needed to find a solution to the problem of soil erosion and decreased soil quality. A study was conducted during the 2021/2022 and 2022/2023 cropping seasons to evaluate the synergistic effect of the tillage system (TS) and manure rates (MR) on selected soil properties at the University of Limpopo Experimental Farm (Syferkuil) and University of Venda Experimental Farm (UNIVEN). The experiment had a split plot design with three replications. The main plots used conventional (CON) and in-field rainwater harvesting (IRWH) tillage systems, while subplots used poultry and cattle manure at rates of 0, 20, and 35 t ha−1. Bulk density (BD), aggregate stability (AS), pH, total N, organic carbon (OC), available P, and exchangeable cations (Ca, Mg, and K) were determined. IRWH significantly increased AS in the 0–20 cm soil layer at Syferkuil. TS × MR interaction significantly influenced AS and total N in the 20–40 cm soil layer during the 2022/2023 season at Syferkuil. IRWH significantly increased Mg content in the 2021/2022 season and total N, OC, and Mg content in the 2022/2023 season at Syferkuil over CON. At UNIVEN, CON significantly increased total N, whereas IRWH increased available P in the 2022/2023 season. MR significantly increased AS, exchangeable Ca, Mg, and K at both sites. At Syferkuil, MR significantly increased total N, OC, and available P during both seasons, whereas at UNIVEN the significant increase was observed on OC and available P during both seasons and total N in the 2021/2022 season. It was found that IRWH and poultry manure (35 t ha−1) improved most soil properties at both sites; however, this study recommends long-term experiments to investigate the combined effect of IRWH and manure rate on soil properties to validate the findings observed in this study.

Long-Term Manuring and Fertilization Influence on Soil Properties and Wheat Productivity in Semi-Arid Regions

Information on the long-term effects of the addition of organics and fertilizers to wheat under the pearl millet–wheat cropping system with semi-arid conditions in north-western India is still lacking. The present research was conducted in an ongoing field experiment initiated during Rabi 1995 at the Research Farm of Chaudhary Charan Singh at Haryana Agricultural University, Hisar. After 25 years, the impacts of nutrient management practices on soil fertility and wheat productivity were evaluated. The experiment comprised a total of eight treatment combinations viz. half and full doses of recommended fertilizers (N and P), organic manures (FYM: farmyard manure, POM: poultry manure, and PRM: press mud) alone and in combination with NP fertilizers. The conjoint application of organic manure and chemical fertilizers resulted in a positive influx of nutrients via increasing total organic carbon (TOC), available N, P, K, and S, which ranged from 0.46 to 1.42%, 122.70 to 194.70, 15.66 to 74.92, 340.5 to 761.2, and 15.26 to 54.63 kg ha−1 in surface soil (0–15 cm), respectively. Carbon fractions and crop yield were significantly improved by adopting integrated nutrient management (INM). The TOC showed a positive and significant correlation with C fractions (r > 0.92) and with soil-available N, P, K, and S (r > 0.77) content. The data also revealed a strong relationship between TOC and soil-available (0–15 cm) nutrients i.e., available N (R2= 0.769), available P (R2 = 0.881), available K (R2 = 0.758), and available S (R2 = 0.914), respectively. Thus, practices that increased TOC were also beneficial in enhancing the availability of the nutrients in the soil. A positive and highly significant correlation was also found among wheat yield, nutrient (NPKS) content, and uptake. A polynomial relationship between grain yield and grain N (R2 = 0.962), P (R2 = 0.946), and K (R2 = 0.967) content, and between straw yield and straw N (R2 = 0.830), P (R2 = 0.541) and K (R2 = 0.976) content was obtained. Integrated use of PRM7.5 followed by FYM15 and POM5 coupled with NP fertilizers proved best, which could be beneficial for obtaining nutritious and highest wheat yield (grain: 6.01 t ha−1 and straw: 7.70 t ha−1) coupled with improved fertility within a sustained manner under the pearl millet–wheat sequence in prevailing semi-arid conditions of the North Indian state of Haryana.

Correction to: Enhanced Nitrogen Use and Economic Benefits in Organic Vegetable Fields via Appropriate Manure Application in Northwestern China

Correction to: Enhanced Nitrogen Use and Economic Benefits in Organic Vegetable Fields via Appropriate Manure Application in Northwestern China

Geochemical Interaction and Bioavailability of Zinc in Soil Under Long‐Term Integrated Nutrient Management in Pearl Millet–Wheat System

ABSTRACTThe degree and severity of zinc (Zn) deficiency in soil reduced the agricultural yield and quality, thus encouraging malnutrition in humans worldwide. The study was hypothesized to increase the bioavailability and release of Zn in soil and Zn biofortification in wheat grains under integrated nutrient management (INM). The long‐term (54 years) experiment laid out in a split‐plot design comprising single (W) and dual (PW) applications of farmyard manure (FYM) (0, 5, 10, and 15 Mg ha−1) and nitrogen (0, 60, and 120 kg ha−1) was studied to understand the distribution of different Zn fractions in soil and their relationship to wheat grain yield and Zn uptake. A laboratory incubation study was performed on surface soils to evaluate the release kinetics of native Zn at field capacity. The different fractions of Zn in soil increased with increasing frequency and levels of FYM application. Residual Zn constituted the maximum proportion (89.03%) of total soil Zn. A high positive correlation (p < 0.01) of diethylenetriaminepentaacetic acid (DTPA)‐extractable Zn and total grain Zn content were observed with different Zn fractions. The release kinetics of native soil Zn increased up to 10 days and became almost constant, indicating the establishment of chemical equilibria between the soil solid and solution phase. Thus, long‐term INM ensured higher wheat production (6.08 Mg ha−1) and Zn biofortification (38.95 mg kg−1) to combat Zn malnutrition and achieve the United Nations’ sustainable development goals on “zero hunger” and “good health and well‐being.”

Effect of long-term application of pig slurry and NPK fertilizers on trace metal content in the soil.

One of the goals of sustainable agricultural production is to avoid soil contamination by elements defined as trace metals (TMs). The aim of this study was to assess the long-term impact of the use of pig slurry (PS) and NPK mineral fertilizers on the soil content of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). In a 9-year crop rotation, PS was used three times only before root crops. The same four levels of NPK doses (N0P0K0, N1P1K1, N3P2K2, N4P2K2) were applied to both plots with and without PS. Soil samples were collected in early spring from topsoil (0-0.3m) and subsoil (0.3-0.6m). Three forms of TMs were determined in the soil: pseudo-total (Aqua regia); bioavailable (Mehlich 3 method) and readily bioavailable (mobile) forms (1M NH4NO3). The tested factors did not have a significant impact on the Cd, Cu and Pb content, regardless of the form analyzed and the soil depth. PS application significantly increased the content of bioavailable forms of Zn regardless of the year, and the content of pseudo-total Zn only in the sugar beet year, i.e. after manure application. Increasing NPK doses increased the content of mobile Zn in the topsoil, especially in PS plots. A tendency to accumulate mobile forms of Cd and Pb was also observed on NPK-fertilized plots. Thus, long-term application of high NPK doses may increase the risk of contamination of the food chain with these metals. The content of mobile Cd and Zn was positively related to the content of total nitrogen in the soil and negatively related to pH.

Effect of Long-Term Fertilization Practices on the Stability of Soil Organic Matter in the Northeast Black Soil Region in China

Soil organic matter (SOM) is an important carbon pool in terrestrial ecosystems and plays a key role in soil functions. Nevertheless, the effects of fertilization practices on the physical, chemical, biological, and comprehensive stability of SOM are still unclear. We carried out a long-term field experiment in the northeast black soil region in China with four different fertilization practices: no fertilizer (CK), single chemical fertilizer (NPK), chemical fertilizer + straw (NPKJ), and chemical fertilizer + organic manure (NPKM). The content of particulate organic matter (POM) and mineral-associated organic matter (MAOM), compound composition of SOM, carbon mineralization characteristics, active soil organic matter (ASOM), and inert soil organic matter (ISOM) were tested. The results showed that the application of fertilizers significantly increased the contents of POM and MAOM to 2.59–4.65 g kg−1 and 32.69–34.65 g kg−1 (p < 0.05), but decreased the MAOM/POM values by 37.8–42.4%, indicating reduced the physical stability of SOM. Fertilization practices increased the contents of aromatic, nitrogen-containing compounds and decreased the oxygen compounds of SOM, representing enhancement of the chemical stability. The contents of ASOM and ISOM increased in fertilization practices, while the biological stability index (BSI) under the NPKJ and NPKM treatments was lower than the CK treatment, suggesting that the biological stability decreased under the manure and straw application. In addition, the comprehensive stability of SOM increased by 26–116% through a reduction in the physical and biological stability, coupled with an increase in the chemical stability. Collectively, our study demonstrated that the application of manure and straw enhanced both the comprehensive stability and content of SOM and reduced the physical and biological stabilities while increasing the chemical stability, which made the largest contribution to the comprehensive stability.

The Effect of Farmer’s Cognition on the Inconsistency Between Behavior and Intention in Manure Application

Manure utilization in China is below optimum due to the inconsistency between farmers’ behavior and their intention to apply manure to their crops. With increasing constraints on the availability of chemical fertilizer and their impact on the environment, understanding how farmers’ perceptions affect their intention and behavior toward manure application is an issue for the implementation of sustainable agricultural development. This study uses primary survey data from 653 farmers. A probit model was used to assess the influence of cognition on farmers’ intentions, behavior, and the inconsistency between them in the use of manure application. Heterogeneity analysis was conducted to identify differences between farmers with different education levels and operation scales. The results showed that enhancing subjective norms, perceived behavioral control, and behavioral attitudes could increase their intention and behavior. Furthermore, improving the perceived behavioral control and behavioral attitudes of farmers would reduce the inconsistency between behavior and intention. In addition, some differences were identified in the role of farmers’ cognition with different education levels and operation scales. In general, it is necessary to enhance farmers’ comprehensive cognition of the value of manure through publicity and popularization of technology, reduce farmers’ perceptions about difficulties in applying manure through new policies and subsidies, and stimulate farmers’ enthusiasm to participate in the practice.

Enhancing soil quality for sustainable agricultural practices in Subak rice fields

Understanding the soil quality of Subak rice fields in Bali is crucial for maintaining agricultural sustainability. This study aimed to explore aspects of soil quality, identify limiting factors, and offer guidance on sustainable land management. Utilizing survey methods, laboratory analysis, and soil quality determination, soil samples were selectively collected from each land unit (LU). LU selection was based on overlays of Subak zonation, soil type, slopes, rainfall, and elevation using Geographic Information System (GIS) techniques. Key soil quality indicators were assessed, including bulk density, texture, porosity, moisture content, pH, organic carbon, cation exchange capacity, base saturation, and nutrients (N, P, K). Overall, soil quality in the study area is classified as good in all LUs, but with significant variations in Soil Quality Index (SQI) values, suggesting the need for tailored management recommendations. Limiting factors include soil texture, organic carbon content, total nitrogen, available phosphorus, and biomass C. Recommended soil management practices include single plow tillage and the application of manure, urea, and SP-36 fertilizer on paddy fields. This approach aims to enhance land productivity sustainably while upholding environmental conservation and the principles of Subak, which have historically maintained a balanced and sustainable agricultural ecosystem.

Rising CO2 and land use change amplify the increase in terrestrial and riverine export of dissolved organic carbon over the past four decades

The lateral transport of dissolved organic carbon (DOC) from land to rivers and oceans is a significant but overlooked component of the global carbon cycle. However, there are still large uncertainties in the magnitude and trend of global DOC export fluxes, as well as their response to environmental change. In this study, several simulations were conducted using a developed land surface model that considered riverine DOC transport and anthropogenic disturbance to investigate the terrestrial DOC loading and riverine DOC export, and to quantify the relative contributions of natural and anthropogenic factors over the past four decades (1981–2016). These factors include climate change, nitrogen deposition, land use change, atmospheric CO2 concentration, anthropogenic water regulation, and fertilizer and manure application. Results showed that the average global annual terrestrial DOC loading was about 432.30 ± 53.59 Tg C yr−1, and rivers exported about 209.73 ± 36.58 Tg C yr−1 to oceans over the past four decades. Simultaneously, a significant increase in terrestrial DOC loading and riverine DOC export fluxes (3.36 Tg C yr−2 and 2.99 Tg Cyr−2, p < 0.01) was found, which increased by 26.88 % and 47.02 %, respectively. According to our factorial analysis, the interannual variability in DOC fluxes in most regions was mainly attributed to climate change and contributed more than 60 % of the long-term increase. In addition, rising atmospheric CO2 and land use change amplified the increase in terrestrial DOC loading, with the area dominated by the two factors expanding from 7.94 % in the 1980s to 23.84 % in the 2010s, and riverine DOC export showed a similar pattern, which may be related to the increased soil DOC sources. Anthropogenic water regulation and nitrogen addition have led to a slight increase in DOC fluxes, which should not be ignored, otherwise carbon fluxes may be underestimated.

How Pharmaceutical Residues Occur, Behave, and Affect the Soil Environment.

Many pharmaceuticals (PhMs), compounds for the treatment or prevention of diseases in humans and animals, have been identified as pollutants of emerging concern (PECs) due to their wide environmental distribution and potential adverse impact on nontarget organisms and populations. They are often found at significant levels in soils due to the continuous release of effluent and sludge from wastewater treatment plants (WWTPs), the release of which occurs much faster than the removal of PhMs. Although they are generally present at low environmental concentrations, conventional wastewater treatment cannot successfully remove PhMs from influent streams or biosolids. In addition, the soil application of animal manure can result in the pollution of soil, surface water, and groundwater with PhMs through surface runoff and leaching. In arid and semiarid regions, irrigation with reclaimed wastewater and the soil application of biosolids are usual agricultural practices, resulting in the distribution of a wide number of PhMs in agricultural soils. The ability to accurately study the fate of PhMs in soils is critical for careful risk evaluation associated with wastewater reuse or biosolid return to the environment. The behavior and fate of PhMs in soils are determined by a number of processes, including adsorption/desorption (accumulation) to soil colloids, biotic (biodegradation) and abiotic (chemical and photochemical degradation) degradation, and transfer (movement) through the soil profile. The sorption/desorption of PhMs in soils is the main determinant of the amount of organic chemicals taken up by plant roots. The magnitude of this process depends on several factors, such as crop type, the physicochemical properties of the compound, environmental properties, and soil-plant characteristics. PhMs are assumed to be readily bioavailable in soil solutions for uptake by plants, and such solutions act as carriers to transport PhMs into plants. Determining microbial responses under exposure conditions can assist in elucidating the impact of PhMs on soil microbial activity and community size. For all of the above reasons, soil remediation is critical when soil pollutants threaten the environment.

The application of organic mulch and chicken manure for improving soil water availability and yield of turmeric (Curcuma domestica Val) in an Inceptisol of Jambi, Indonesia

Turmeric (Curcuma domestica Val) is one of the agricultural commodities being developed by the Jambi Province of Indonesia. However, despite the high value of turmeric, its productivity in Jambi Province is low. This is because the crop is mostly cultivated in marginal lands dominated by Inceptisol, which has low fertility and low water availability. Organic mulch and chicken manure have the potential to be used to improve soil water availability and crop yield. This research aimed to evaluate the effect of organic mulch cover and chicken manure on soil water availability and turmeric yield. The treatments tested were combinations of various percentages of organic mulch cover (30%, 60%, and 90%, and chicken manure dosage (0, 5, 10, and 15 t ha-1). The twelve treatment combinations were arranged in a randomized block design with three replications. The results showed that the combination of the percentage of organic mulch cover and chicken manure dosage affected soil organic matter content, soil bulk density, soil pore size distribution, soil water availability, and turmeric yield. The application of 30% cover of organic mulch and 10 t ha-1 of chicken manure was found to be the best combination to improve soil available water and turmeric yield. The regression analysis results showed that soil bulk density, organic carbon, fast-drainage pores, and slow-drainage pores simultaneously affected the soil water content, with an R2 value of 0.85. The results of this study proved that soil available water is also closely correlated with turmeric yield.