Average Soil pH Research Articles

Soil Quality Assessment in Tourism-Disturbed Subtropical Mountain Meadow Areas of Wugong Mountain, Central Southeast China.

Meadow soil is a vital ecosystem component and can be influenced by meadow vegetation. Evaluating soil quality in mountain meadows subjected to different levels of tourism disturbance is essential for scientific research, ecological restoration, and sustainable management. This study aimed to evaluate meadow soil quality at different tourism-disturbance levels and attempted to establish a minimum data set (MDS) with compatible indicators for soil quality assessment of subtropical mountain meadows. We analyzed fifteen soil physical, chemical, and biological indicators in control check (CK), light disturbance (LD), medium disturbance (MD), and severe disturbance (SD) meadow areas in Wugong Mountain, west of Jiangxi, China. In addition, a soil quality index (SQI) was determined using the established MDS based on the integrated soil quality index. Average soil permeability, soil pH, available nitrogen (AN), available phosphorus (AP), and number of fungal OTUs were finally introduced into the MDS to evaluate meadow soil quality at different tourism-disturbance levels. The study found that the soil of the Wugong Mountain meadow was acidic, the bulk density was loose, and the nutrient content was rich. Additionally, SQI decreased with increase in tourism-disturbance level. The mean SQI values of the Wugong Mountain meadow areas were: CK, 0.612; LD, 0.493; MD, 0.448; and SD, 0.416. Our results demonstrate that the SQI based on the MDS method could be a valuable tool with which to indicate the soil quality of mountain meadow areas, and the SQI can be regarded as a primary indicator of ecological restoration and sustainable management.

Accelerated carbonate dissolution caused by anthropogenic acidification - contrast of watershed soils to lake sediments in Taihu Region, China.

Although Taihu watershed is an "acid-insensitive" region, anthropogenic acidification has greatly changed the water chemistry in Taihu Lake. However, how soil carbonates responded to the long-term human-induced acidification received less attention. In this work, we investigated soil carbonate concentrations from different land uses in the upstream of the lake and sediment carbonate profiles in the lake, to explore the linkage of carbonates dissolution in the land and sedimentation in the lake. The result showed that the wheat-rice surface soil, the most acidification-impacted by fertilization and acid deposition, had significantly lower pH than vegetable and wetland soils (p < 0.05). Meanwhile, the carbonate concentration in wetland soils, only impacted by acid deposition, was significantly higher than that in wheat-rice and vegetable soils (p < 0.05). The pH profile of fertilized soils, with an increasing trend from the surface to bottom, further indicated the acidifying effect of fertilization. Although the average soil pH across all land uses was 6.6 in the upstream of the lake, remaining carbonate buffering system, the significant carbonate decrease especially in surface soils evidenced the definite carbonate dissolution by acidification, which is cumulative and irreversible. Contrary to the topsoils, the sediment carbonate concentration presented an increasing trend from the depth of 15cm (denoting around the early 1980s) to the surface, indicating that lake sediment is a major sink of carbonate Ca and Mg from the watershed, particular under an alkaline lake environment caused by frequent algae blooms in the past decades. In addition, Ca/Mg ratio in the sediment, having higher values in a higher pH environment, was quite different from the watershed soil pattern, suggesting different biogeochemical processes Ca and Mg underwent during their transportation and sedimentation. The effects of acidification-altered re-distribution of carbonate Ca and Mg and Ca/Mg ratio in the terrestrial and aquatic environments deserve wider considerations of ecosystem consequence.

Better performance of compound fertilizers than bulk-blend fertilizers on reducing ammonia emission and improving wheat productivity

Compound fertilizer and bulk-blend fertilizer are two major types of fertilizers used in wheat production. However, it remains unclear which type of fertilizers has lower ammonia (NH3) emission and greater wheat productivity. We conducted a field experiment in Hefei, China during 2018–2019 and 2019–2020 wheat growing seasons. The objectives were to assess the effects of three compound fertilizers and three bulk-blend fertilizers on NH3 emission and wheat growth, and elucidate the mechanisms involved. The seven treatments included the control test without N application (CK), bulk-blend fertilizer (BF), bulk-blend fertilizer with bentonite (BFb), bulk-blend fertilizer with humic acid (BFh), compound fertilizer (CF), compound fertilizer with bentonite (CFb), and compound fertilizer with humic acid (CFh). Results showed that compared with bulk-blend fertilizers, the corresponding compound fertilizers decreased total area-scaled NH3 emissions by 10.2%−19.2% and yield-scaled NH3 emissions by 12.8%−23.5%, increased average soil nitrification rate by 7.2%−20.9%, and reduced average soil NH4+ content by 7.2%−16.8% and average soil pH by 0.3%−1.0%. Greater soil nitrification rate in compound fertilizer treatments was partly responsible for the decreases in soil NH4+ content, soil pH, and NH3 emission, and then led to the increases in soil inorganic N content, grain yield, and N use efficiency. Compared with bulk-blend fertilizers, the corresponding compound fertilizers increased grain yields by 2.3%−12.2% and N use efficiency by 8.6%−43.9% (except for CF in 2019–2020). Overall, compound fertilizers had better performances than bulk-blend fertilizers in reducing NH3 emission (area-scaled and yield-scaled) and improving wheat productivity; while adding functional materials (e.g., bentonite and humic acid) and using proper application methods (e.g., banded application) are possible strategies for decreasing NH3 emission from bulk-blend fertilizers.

Effects of Straw Returning on Soil Ammonia Volatilization Under Different Production Conditions Based on Meta-analysis

In order to explore the response of Chinese farmland soil ammonia volatilization to straw returning to the field under different production conditions, this study used no straw returning as a control. Through the collection of published literature test data, the Meta-analysis method was used to quantitatively study the effects of different natural factors and, under the conditions of farmland management measures, the effect of returning straw to the field on the emission reduction of soil ammonia volatilization. At the same time, through partial correlation analysis, the main influencing factors of ammonia volatilization under the condition of returning straw to the field were found, and the ammonia volatilization was quantified. The results showed that the effect of straw returning on soil ammonia volatilization decreased with the increase in accumulated rainfall during the growth period and increased with the increase in average temperature during the growth period. When the soil pH was less than 6, straw returning to the field significantly promoted soil ammonia volatilization, and when the pH was ≥ 6, returning straw to the field significantly inhibited ammonia volatilization in the soil. The reduction effect of returning straw to the field on soil ammonia volatilization increased with the increase in soil clay content. When the total soil nitrogen content was <0.1% and >0.2%, returning the straw to the field significantly inhibited the volatilization of soil ammonia, and when the total soil nitrogen content was between 0.1% and 0.2%, returning the straw to the field significantly promoted the volatilization of ammonia from the soil. When the nitrogen application rate was 60-180 kg·hm-2 and the nitrogen application rate was >240 kg·hm-2, returning straw to the field significantly reduced soil ammonia volatilization (P<0.05), and when nitrogen application rate was 180-240 kg·hm-2, returning straw to the field significantly promoted ammonia volatilization in the soil. Returning straw to the field by plowing or rotary tillage significantly inhibited ammonia volatilization in the soil, whereas returning straw to the field in a mulching mode had no significant effect on ammonia volatilization. When the straw C/N>45, it significantly inhibited ammonia volatilization from the soil, and when the straw C/N ≤ 45, the straw returning to the field significantly promoted the ammonia volatilization of the soil. The reduction effect of straw returning on ammonia volatilization increased with the increase in straw-returning amount. In non-paddy fields, returning straw to the field had a significant inhibitory effect on soil ammonia volatilization, and in paddy fields, returning straw to the field had a significant effect on soil ammonia volatilization. The results of partial correlation analysis showed that in paddy fields, the average growth period and soil pH were the main factors affecting soil ammonia volatilization under the condition of returning straw to the field, and in non-paddy fields, nitrogen application rate and straw C/N were the main factors affecting the conditions. This study can provide reference for the scientific and rational use of straw to achieve ammonia volatilization emission reduction in farmland.

KARAKTERISTIK HABITAT DAN PERSEBARAN RHIZANTHES LOWEII. (BECC) HARM DI TAMAN NASIONAL KERINCI SEBLAT RESORT SUNGAI LAMBAI

Indonesia is known as one of the countries with the largest biodiversity in the world (megadiversity) and is the center of world biodiversity (megacenter of biodiversity). Rhizanthes loweii has a geographic distribution from Sumatra, Peninsular Malaysia, and Kalimantan. In Sumatra this species has been recorded to be found in Mount Leuser, Sibolangit, Mount Dempo, South Sumatra, Penanggungan, Lampung and Bengkulu. KSNP as one of the largest conservation areas in Indonesia has a very high and diverse potential for natural resources and environmental services. TNKS also has various data objects of natural tourist attractions that have the potential to be developed, including mountains, hills, lakes and waterfalls. This research was conducted in the Kerici Seblat National Park (TNKS) Resort Sungai Lambai. The method that will be used in collecting data in this research is the path method and the determination of the observation plot is carried out by purposive sampling. Each 1 ha measuring plot counted the number of individuals with Rhizanthes loweii buds/flowers. This Important Value Index (INP) is used to determine the species composition and dominance of a species in a stand. Sungai Lambai Resort is located in Nagari Lubuak Gadang Selatan, Sangir District, South Solok Regency, West Sumatra. Nagari Lubuak Gadang Selatan is divided into five jorongs, namely, Jorong Pincuran Tujuh, Jorong Sungai Lambai, Jorong Karang Putiah, Jorong Ayia Manyuruak and Jorong Liki. The vegetation around Rhizanthes loweii contained in the research plot amounted to 32 species with seedling, sapling, pole and tree levels. The soil in this research location is generally alkaline soil. The type of clay soil is dusty, has a smooth texture, and is blackish brown in color. Habitat characteristics and distribution of Rhizanthes loweii in Kerinci Seblat National Park lives on dusty clay soil with blackish brown color and average soil pH of 7.1 (neutral). The average temperature is 23.7⁰ C and the average humidity is 80%.Keywords: TNKS, Habitat, Distribution, Rhizanthes loweii. (Becc)

An ecological enumeration of pteridophytic flora from Pithoragarh, Central Himalayan province (U.K.) India

Terrestrial ecological survey, preparation of comprehensive checklist, soil analysis in relation to fern diversity and growth were the main objectives of the study in Pithoragarh, Uttarakhand. Classification, taxonomy, identification, nomenclature, and conservation status of Pteridophytes were done by autistic, viable and suitable literature. Soil analysis was done by a specific given protocol separately. In our study, a total of 17 families, 27 genera, and 37 species of Pteridophyta were recorded. Various types of habitat for this flora were noticed, including Lithophytes, moist places, Mesophyll, forest floor, and epiphyte. The average soil pH was 6.7, organic carbon was 1.923%, nitrogen was 0.406%, phosphorus was 3.40 ppm and potassium was 31.33 ppm, all recorded at the site of study. Most species were noticed as common in all the spots, but Pteridium aquilinum and Christella arida were the main rare species in the area.

Mapping Spatial Management Zones of Salt-Affected Soils in Arid Region: A Case Study in the East of the Nile Delta, Egypt

Soil salinization is a global problem that affects a large part of the world, especially arid and semi-arid regions. Hence, diagnosing soil salinity is the first step towards appropriate management. The current work aims to assess and map soil salinity in the eastern Nile Delta using principal component analysis (PCA). In order to develop appropriate solutions for rational management to mitigate the impacts of soil salinization and increase yield production 34 soil profiles were dug that covered the variation in the soils located at the northeast of the Nile delta. The spatial variation of soil parameters was mapped using ordinary kriging interpolation. The results of PCA illustrated that, among the studied soil properties, soil electrical conductivity (ECe), sodium adsorption ratio (SAR), exchangeable sodium percent (ESP), and bulk density (BD), are the critical factors affecting management practices in the Nile Delta. Two spatial management zones (SMZ) were identified; SMZ 1 occupied 45.04% of the study area and SMZ2 occupied 54.96% of the study area. The average of soil pH, ECe, SAR, CEC, ESP and BD were 8.31, 20.32 dSm−1, 47.19, 32.9 cmolckg−1, 32.85% and 1.47 Mgm−3 for the first cluster (SMZ1), respectively. In addition, the second cluster (SMZ2) had average soil pH, ECe, SAR, CEC, ESP and BD of 7.75, 12.30 dSm−1, 26.6, 25.23 cmolckg−1, 26.6% and 1.27 Mgm−3. The results showed p-value &lt; 0.05 which confirms that there is a significant statistical difference between the two zones. Finally, the results obtained could be used as a fundamental basis for improving agricultural management practices in such salt-affected soils.

KEANEKARAGAMAN SERANGGA PERMUKAAN TANAH DI KAWASAN BUKIT GATAN KABUPATEN MUSI RAWAS

This study aims to determine the diversity of soil surface insects, in the Bukit Gatan area, Musi Rawas Regency. This research is a qualitative descriptive study using a pitfall trap and using a random sampling method. The results showed that the types of ground surface insects contained 3 orders, 5 families and 10 species.The results of the analysis of the ecological index of soil surface insects in the Gatan hill area, Musi Rawas Regency, namely the diversity index (H') 1.241 in the low category, Evennes index (E') 0.64 in the medium category, and the dominance index (C)0.277 in the medium category.The abiotic factors in the Bukit Gatan area, Musi Rawas Regency at the research site are the average air temperature 29℃, average soil pH 6.5, and average soil moisture 85.3%.Diversity of soil surface insects in the Bukit Gatan area, Musi Rawas Regency is in the low category.

Effect of Plastic Film Mulching on Methane and Nitrous Oxide Emissions from the Ridges and Furrows of a Vegetable Field

Investigate the effects of plastic film mulching on CH4 and N2O emissions from a vegetable field, a one-year in situ field observation was conducted using a static opaque chamber in a pepper-radish cropping system at the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China at Southwest University, Chongqing. Two treatments (conventional and film mulching) were used to study the influence of film mulching on CH4 and N2O emissions. The results showed that mulching significantly increased the annual average soil pH (P<0.01), annual surface and subsurface (5 cm) temperature (P<0.05), and soil moisture content during the radish-growing season (P<0.05). The mulching also significantly reduced CH4 emissions in the field ridges (P<0.05); the average CH4 flux from ridges during the pepper-growing season was 0.110 mg·(m2·h)-1 and 0.028 mg·(m2·h)-1, and 0.011 mg·(m2·h)-1 and -0.019 mg·(m2·h)-1 during the radish-growing season, under the conventional and film mulching treatments, respectively. However, across the entire experiment, CH4 flux from field furrows was not significantly different between the two mulching treatments (P>0.05), with mean flux values during the pepper-growing season of 0.058 mg·(m2·h)-1 and 0.057 mg·(m2·h)-1, and 0.083 mg·(m2·h)-1 and 0.092 mg·(m2·h)-1 during the radish-growing season, for conventional and plastic film mulching, respectively. Except for the conventional treatment during the pepper-growing season, CH4 emissions from ridges were significantly higher than from furrows, but for other treatments, including conventional and film mulching treatments during radish-growing season and film mulching treatment during the pepper-growing season, the CH4 emissions from furrows were all significantly higher than those from ridges. This was related to the stable anoxic environment created in furrows under high rainfall conditions in Southwest China. The N2O emission flux from the ridges during the pepper-growing season was 65.41 μg·(m2·h)-1 and 68.39 μg·(m2·h)-1 under the conventional and film mulching treatments, respectively, and the N2O emission flux during the radish-growing season was 78.43 μg·(m2·h)-1 and 66.19 μg·(m2·h)-1, respectively. The N2O flux between conventional treatment and film mulching treatment in ridges or furrows were not significantly different (P>0.05), while the N2O emissions from the ridges were significantly higher than that from the furrows. CH4 emission flux was significantly positively correlated with surface and subsurface temperature, while N2O emission flux was only significantly positively correlated with alkaline nitrogen and ammonium nitrogen content.

Cross‐linked polymers increase nutrient sorption in degraded soils

AbstractCross‐linked polymer hydrogels, polyacrylamide co‐polymer (XPAM) or polyacrylate (XPAA) offer potential solutions for soil degradation, declines in soil resilience, and poor productivity in marginal soils. However, little is known about their long‐term effect on soil nutrient availability. This 9‐yr, irrigated, outdoor, cropped pot study evaluated a single, one‐time addition of XPAM or XPAA at 0.25 or 0.5% dry wt. (5.6 or 11.2 Mg ha–1) in a degraded (artificially eroded) soil. Controls included an unamended degraded soil and an unamended, non‐degraded soil (i.e., topsoil). We measured nutrients in soil and leachate water each year, and in the first 5 yr, crop yields and nutrient uptake. Both hydrogels increased average soil pH and electrical conductivity (EC), soil extractable K, Na, and total organic carbon (TOC), and decreased soil extractable Mg relative to the control. Unlike XPAM, XPAA produced a greater increase in soil extractable K, increased extractable Fe, Zn, Mn, and Cu, increased Olsen P, and decreased total inorganic carbon (TIC). Neither hydrogel affected crop yields but XPAA increased K and Zn and decreased Mg and Na uptake in crops compared to controls. Relative to the control, both hydrogels decreased cumulative Ca, Mg, and S leaching mass losses and increased mean EC of leachate. Unlike XPAM, XPAA increased cumulative leaching mass losses of K, P, NO3–N, and NH4–N relative to the control. The hydrogels’ soil effects persisted for ≥7 yr, differing as a function of the quantity of included counterions and the stability of the gel structure after soil placement.

Distribution of pyrite depth and soil properties in fresh water swampland in North Candi Laras Sub-district, South Kalimantan Province

One of the challenges of swamp land utilization for agricultural uses is the existence of pyrite (FeS2), especially in the top soil. The aim of this research was to study the distribution of pyrite position with depth and soil properties in fresh water swamp land in North Candi Laras Sub-district, Tapin Regency, South Kalimantan Province. Pyrite layer was determined by using hydrogen peroxide (H2O2) and its unique reaction was marked by foam existence with soil pH <2.5. Ten soil samples analyzed to determine physical and chemical properties. The result of this research showed that pyrite depth varied from 25 cm to >100 cm. The depths of pyrite material were grouped into 25 to 50 cm, 51 to 75 cm, 76 to100 cm, and 101 to 150 cm. The closer to the river, pyrite depth in the soil was deeper. The pyrite depth affected soil pH and cations. Soils containing pyrite material were very acidic with an average field soil pH 4.0 to 4.5. Cation Ca, K, Na levels were higher with the shallower pyrite depth in the soil, meanwhile Mg was almost same in all pyrite depth groups. The information of pyrite position within the soil is useful for controlling water table management to prevent pyrite oxidation.

The Influence of Climate, Soil Properties and Vegetation on Soil Nitrogen in Sloping Farmland

Soil nitrogen in farmland ecosystems is affected by climate, soil physical and chemical properties and planting activities. To clarify the effects of these factors on soil nitrogen in sloping farmland quantitatively, the distribution of soil total nitrogen (TN) content, nitrate nitrogen (NO3-N) content and ammonium nitrogen (NH4-N) content at depth of 0–100 cm on 11 profiles of the Luanhe River Basin were analyzed. Meanwhile, soil physical and chemical properties, climatic factors and NDVI (Normalized Difference Vegetation Index) were used to construct a structural equation which reflected the influence mechanism of environmental factors on soil nitrogen concentration. The results showed that TN and NO3-N content decreased with the increase of soil depth in the Luanhe River Basin, while the variation of NH4-N content with soil depth was not obvious. Soil organic carbon (SOC) content, soil pH, soil area average particle size (SMD) and NDVI6 (NDVI of June) explained variation of TN content by 77.4%. SOC was the most important environmental factor contributing to the variation of TN content. NDVI5 (NDVI of May), annual average precipitation (MAP), soil pH and SOC explained 49.1% variation of NO3-N content. Among all environmental factors, only NDVI8 (NDVI of August) had significant correlation with soil NH4-N content, which explained the change of NH4-N content by 24.2%. The results showed that soil nitrogen content in the sloping farmland ecosystem was mainly affected by natural factors such as soil parent material and climate.

Karakteristik Kondisi Mangrove di Desa Taddan Kabupaten Sampang

Mangroves are intertidal plants found along tropical and non-tropical coastlines which is flooded by tides in brackish areas. Mangroves ecosystems have experienced a very large decrease in area especially in Madura region. This research was conducted in Taddan Village, Camplong District, Sampang. The objectives of this research were to identify mangrove vegetation, mangrove area and mangrove characteristics. The area of mangroves in the research location was 48 ha. There were 7 types of mangroves found, e.g Rhizophora apiculata, Rhizophora stylosa, Rhizophora mucronata, Sonneratia alba, Sonneratia caseolaris, Avicennia marina and Avicennia alba. The type of substrate in the mangrove research location was mainly mud. The distribution pattern of mangroves at the research location tends to spread in groups, with a low level of mangrove diversity. The uniformity index value is balanced, or in other words, there are individuals who dominate. The average sediment depth is 24.7 cm, the average salinity is 36.7 ppt, the average water pH is 5.3, the average DO is 5.9 mg / l, the average water temperature is 31, 70C, the average soil pH is 6.4. Further analysis concluded that environmental parameters in the area was unsuitable for marine tourism.

Variation in biosynthesis of an effective anticancer secondary metabolite, mahanine in Murraya koenigii, conditional on soil physicochemistry and weather suitability

Murraya koenigii (MK) leaf being a rich source of bioactive secondary metabolites has received inordinate attention in drug development research. Formation of secondary plant metabolite(s) in medicinal plants depends on several factors and in this study the cause of variation in bioavailability and content of a vital bioactive phytochemical, mahanine in the MK leaves from different geographical locations of varying soil properties and weather parameters was determined. Accordingly, MK leaves and soil samples around the plant base in quintuplicate from each site across five states of India at similar time point were collected. Mahanine content was determined and compared among samples from different regions. The quantitative analysis data comprised that MK-leaves of southern part of India contains highest amount of mahanine, which is 16.9 times higher than that of MK-leaves of north-eastern part of India (which measured as the lowest). The results suggested that pH, conductivity and bacterial populations of the soil samples were positively correlated with mahanine content in the MK-leaves. For examples, the average soil pH of the southern India sites was in basic range (8.8 ± 0.6); whereas that of the north-east India sites was in slightly acidic ranges (6.1 ± 0.5) and mean soil conductivity value for the north east India soils was 78.3 ± 16.3 µS/cm against mean value of 432.4 ± 204.5 µs/cm for south India soils. In conclusion, this study proclaims that higher level of bioactive phytochemical, mahanine in MK leaves depending upon geographical location, weather suitability and soil’s physiochemical and microbial parameters of its cultivation sites.

Propiedades físicas y químicas del suelo urbano del Bosque San Juan de Aragón, Ciudad de México

Ante la falta de estudios sobre suelos urbanos en México, en el presente trabajo se evaluaron ocho propiedades físicas y químicas empleadas por el Indicador Condición de Suelo del FIA (Programa Nacional de Inventario y Análisis Forestal, de Estados Unidos), para determinar la calidad de los suelos y su papel en el desarrollo de las especies arbóreas del Bosque de San Juan de Aragón. Las propiedades evaluadas y analizadas en términos horizontales y verticales, fueron: pH, conductividad eléctrica, contenido de sales, textura, densidad aparente, y porcentajes de materia orgánica, carbono orgánico y espacio poroso. Se colectaron 96 muestras de suelo sobre 28 sitios de muestreo de 0.1 ha, a tres profundidades, 0-5, 5-10 y 10‑15 cm. El pH promedio del suelo fue 7.2; conductividad eléctrica, 0.51 dS m-1; densidad aparente, 1.02 g cm-3; espacio poroso, 61.84%; sales disueltas totales, 327.20 mg L-1; materia orgánica, 3.6% y carbono orgánico, 2.63%, así como una clase textural franca. Los suelos del área de estudio presentaron variabilidad vertical para densidad aparente, espacio poroso, contenido de materia orgánica, carbono orgánico, conductividad eléctrica y sales solubles, y fueron relativamente homogéneos en sentido horizontal. Con excepción de la materia orgánica, el resto de las propiedades presentaron valores aceptables para el buen desarrollo de las diferentes especies arbóreas presentes en el bosque e identif icadas en estudios previos. La medición de las propiedades evaluadas, permitió obtener un panorama real sobre la capacidad de este suelo urbano para funcionar como soporte adecuado en el desarrollo de especies leñosas.

Soil acidification in Chinese tea plantations.

Soil acidification is a major problem in intensive agricultural systems and is becoming increasingly serious. Most research has reported the soil acidification of cereal crops, forests, and grasslands. However, there is no information about soil acidification under tea cultivation on a national scale. Therefore, we conducted a nationwide survey of soil acidification in the major tea-planting areas of China and used two nationwide surveys in three Chinese counties to evaluate changes in soil acidity over the past 20-30years. Finally, the acidity of soil from forests and traditional and organic tea plantations was compared to evaluate the effects of agricultural management on soil acidification in tea plantations. Our results show that: (1) the average soil pH was 4.68 nationally and ranged from 3.96 to 5.48 in different provinces. Overall, 46.0% of the soil samples had a pH <4.5, which is too acidic for tea growth and only 43.9% had a soil pH of 4.5-5.5, which is optimal for tea growth. (2) In the past 20-30years, the greatest soil acidification was observed in tea plantations; the pH decreased by 0.47 to 1.43, which is much greater than the decrease seen in fruit and vegetable systems (0.40 to 1.08) and cereals (0.30 to 0.89). (3) Compared with forests, tea cultivation with chemical fertilizer application caused serious soil acidification, while no significant acidification was observed at organic tea plantations. In conclusion, serious soil acidification occurs nationally in China, and organic management is an adaptive choice for sustainable tea growth.

Application of ameliorant for improving soil quality and chili (Capsicum annum L.) productivity on degraded acidic upland

Development of agricultural commodities, including for horticulture crops, must lead to suboptimal lands and often already degraded. The study aims to study the effectiveness of organic ameliorant in improving soil quality on degraded acidic upland and its impact on the productivity of chili plants. The study was conducted on acidic upland in Tamanbogo, East Lampung, using a randomized block design with six treatments and three replications. The treatment used 3 ameliorants namely compost, biochar KK-50, Biochar KK-20 with a dose of 20 t ha−1, each combined with and without mulch, the control treatment was without mulch and ameliorant. The results showed that the amelioration treatment had a significant effect on improving soil physical properties, indicated by the average BD values which was significantly lower and the soil porosity was significantly higher. The treatment of biochar also results in significantly higher aeration pores than control treatment. The average soil pH in the control treatment <5, while the average pH in the biochar treatment >5. The average potential soil K content at the biochar treatment was significantly higher. Amelioration treatment has a significant effect on the growth of chili plants. The average chili production in the amelioration treatment was relatively higher than control.

Soil characteristics of natural silver linden (Tilia tomentosa Moench) populations

Studies regarding the determination of the ecological characteristics of the natural distribution areas of the silver linden (Tilia tomentosa Moench) are limited. It is of great importance to select areas with similar natural cultivation characteristics in the plantations established for flower or timber production. Physiographical factors affecting these forests were explored to determine the physical and chemical characteristics of the soil. The soil samples were collected from three natural populations, and a total of 43 samples were examined in terms of aspect, elevation, declivity position, and slope. It was determined that the natural linden populations expanded between the altitudes of 0 m and 400 m and 88% of the populations were denser in aspects with shadow. It was found that 91% of the soil was in the class of “deep to very deep”, 61% showed an expansion in sandy clay loam soils, and 30% showed an expansion in sandy loam soils. Average soil pH ranged between 5.6 and 6.6. The soils were found to be salt-free and slightly limy. In terms of the organic carbon amount, the soils were classified as medium.

Changes in Alberta’s Grasslands Soil pH by Adopting the Adaptive Multi-Paddock Grazing System

Grasslands account for a large percentage of earth’s terrestrial area. Soil is an important aspect of the global carbon cycle and plays a critical role in mitigating climate change. Due to poor land management, the grasslands have been greatly degraded, resulting in the grasslands becoming the most endangered ecosystem on the planet. Fortunately, there are several new techniques that can be implemented in order to help alleviate the negative impacts that the depleted grasslands have had on the earth. The Adaptive-Multi Paddock (AMP) grazing system is an innovative technique that has been introduced as a way to increase plant regrowth, improve animal performance, and increase soil organic carbon (SOC) levels. As SOC has been shown to be correlated to soil pH, there is potential for the AMP system to affect soil pH. To implement the AMP system, a rancher’s land would be divided into multiple small paddocks, and the cattle would be rotated between the paddocks more frequently. Non-AMP managed ranches include any ranch that uses traditional grazing techniques, such as low or high continuous grazing. The purpose of this project was to study the effects of the AMP grazing system on the pH of Alberta’s grassland soil. Soil samples were collected from AMP and Non-AMP managed ranches in Alberta. After the samples were separated into several layers, weighed, dried, and sieved, the pH of each soil section was recorded and analyzed. Using the data from the Albertan ranches, the AMP and Non-AMP managed ranches were compared. From this data, it appears that by using the AMP system, the pH was slightly lower across all soil depths. Soil also appeared to become more basic with each successive layer. Between Alberta’s four ecoregions, the average soil pH seemed to vary. In both AMP and Non-AMP managed ranches, the subsoil was more alkaline while the topsoil was more acidic, which could be a result of possible higher SOC concentrations. In future studies, the pH data from Alberta’s soils will be compared to the Saskatchewan and Manitoba data, which will represent all of Canada’s grassland soil. When the SOC data is collected, the pH and SOC concentration will be analyzed to establish a correlation. Ultimately, farmers might be reimbursed for the additional costs of adopting the AMP system because of the environmental benefits the system could have.

Cropland acidification increases risk of yield losses and food insecurity in China

Distinct cropland acidification has been reported in China due to nitrogen (N) fertilizer overuse. However, the impacts on food production and thereby on food security are largely unknown. Yield losses in the period 1980–2050 were therefore assessed by simulating soil pH changes combined with derived pH-yield relationships for wheat, maize and rice. If the N fertilizer input continues to increase at 1% annually, the predicted average soil pH decline is about one unit and relative yield losses are expected to increase from approximately 4%–24% during 2010–2050. If the N fertilizer increase stops in 2020 (N2020), the expected losses are approximately 16% in 2050, which is comparable to a scenario of 100% crop residue return (100%RR). However, if 30% of the N fertilizer is replaced by manure N (30%MR), the losses reduce to near 5% in 2050. Soil acidification was predicted to reverse and expected losses are only 2.5% in 2050 in a combined scenario of N2020, 100%RR and 30%MR. Our results illustrate the potential food insecurity induced by cropland acidification and address the necessity of mitigation.