Typic Dystrudepts Research Articles

Soil Development and Land Suitability for Cacao on Sandstone and Pumice Breccia in the Semilir Formation in Ponjong District, Gunungkidul Regency, Indonesia

The parent material of the Semilir Formation, which consists of breccia pumice and sandstone, was located in the villages of Sawahan and Umbulrejo, Ponjong district, and it influences the genesis and soil types. This study utilized survey and laboratory analysis methods. Two soil profiles were studied: the first profile was located in Sawahan Village with breccia pumice as the parent material, while the second profile was in Umbulrejo Village with sandstone as the parent material. The research results indicated that soils developed from breccia pumice had diagnostic horizons of umbric epipedon and argillic endopedon with an advanced soil development stage. Soils developed from sandstone had diagnostic horizons of umbric epipedon and cambic endopedon with a young soil development stage. This affects the chemical properties of the soil. Soils formed from pumice breccia tend to have base saturation of less than 50% with low exchangeable bases, while soils formed from sandstone have base saturation of >50% with high exchangeable bases. Soils developed from breccia pumice and sandstone have soil classification as Typic Paleudults and Typic Dystrudepts. These soil types are suitable for cocoa plant cultivation; however, they require mechanical conservation through terrace construction and improved drainage by incorporating organic materials or compost into the soil, which can significantly enhance soil porosity, enabling better water retention and drainage.

Soil Development and Land Suitability for Cacao on Sandstone and Pumice Breccia in the Semilir Formation in Ponjong District, Gunungkidul Regency, Indonesia

The parent material of the Semilir Formation, which consists of breccia pumice and sandstone, was located in the villages of Sawahan and Umbulrejo, Ponjong district, and it influences the genesis and soil types. This study utilized survey and laboratory analysis methods. Two soil profiles were studied: the first profile was located in Sawahan Village with breccia pumice as the parent material, while the second profile was in Umbulrejo Village with sandstone as the parent material. The research results indicated that soils developed from breccia pumice had diagnostic horizons of umbric epipedon and argillic endopedon with an advanced soil development stage. Soils developed from sandstone had diagnostic horizons of umbric epipedon and cambic endopedon with a young soil development stage. This affects the chemical properties of the soil. Soils formed from pumice breccia tend to have base saturation of less than 50% with low exchangeable bases, while soils formed from sandstone have base saturation of >50% with high exchangeable bases. Soils developed from breccia pumice and sandstone have soil classification as Typic Paleudults and Typic Dystrudepts. These soil types are suitable for cocoa plant cultivation; however, they require mechanical conservation through terrace construction and improved drainage by incorporating organic materials or compost into the soil, which can significantly enhance soil porosity, enabling better water retention and drainage.

Pedodiversity and Organic Matter Dynamics in the North Apennines (Italy): Relationships among Soil Types, Biodiversity, and Ecological Functionality

Pedodiversity is generally neglected in studies concerning soil organic carbon (SOC). Therefore, this investigation aimed to explore the effect of soil types on the following: (1) soil processes related to organic matter (OM) dynamics along the profile; and (2) the microbial community and functionality within the uppermost horizon. Humic Dystrudepts (HD), Typic Dystrudepts (TD), and Humic Lithic Dystrudepts (HLD) were selected in beech forests of the Apennine ridge in the Emilia-Romagna Region (Italy). Soils were sampled by horizons until parent material, and physico-chemical and functional analyses were performed. The results showed that both HD and HLD soils had a higher SOC accumulation than TD, particularly within the deeper horizons. Such accumulation might be due to the lower turnover rate of soil OM forms, namely fulvic acid-like substances, humic acid-like substances, and non-extractable OM. Noteworthy, the A horizons showed slight differences in SOC among the soil types, suggesting similar SOC decomposition processes. This fact was confirmed by the lack of differences in microbial DNA-based diversity and functionality. This study highlighted the importance of combining pedodiversity and microbial diversity for a wider perspective on SOC dynamics.

Effect of NBPT-DCD (Urease and Nitrification Inhibitor) on Nitrogen Loss, N Uptake and Oil Palm Yields (Elaeis guineensis Jacq.) bn Typic Dystrudepts Soil

Incorporating N-(n-butyl) thiophosphoric triamide (NBPT) as a urease inhibitor and Dicyandiamide (DCD) as a nitrification inhibitor can enhance the efficiency of nitrogen (N) fertilization. The main aim of the study was to evaluate the impact of urease and nitrification inhibitors (NBPT and DCD) on N loss in urea fertilizer, N absorption, and oil palm (Elaeis guineensis Jacq.) yield. Researchers conducted the field trial using a single-factor, completely randomized design (CRD) with three replications. The experimental treatments included nitrogen (N) fertilization with 5 different levels. The levels were: 100% urea (2.75 kg/plant/year: 1.50 kg/plant in rotation 1 and 1.25 kg/plant in rotation 2) (N0), 80% urea + NBPT-DCD (2.20 kg/plant/year: 1.20 kg/plant in rotation 1 and 1.0 kg/plant in rotation 2) (N1), 60% urea + NBPT-DCD (1.65 kg/plant/year: 0.90 kg/plant in rotation 1 and 0.75 kg/plant in rotation 2) (N2), Urea dosage of 80% (2.20 kg/year: 1.20 kg/plant in rotation 1 and 1.00 kg/plant in rotation 2) (N3), and Urea dosage of 60% (1.65 kg/plant/year: 0.90 kg/plant in rotation 1 and 0.75 kg/plant in rotation 2) (N4). The findings revealed that the application of Urea in combination with NBPT-DCD (inhibitors of urease and nitrification) led to a reduction in N loss by 30.33-37.48% and an increase in N absorption compared to Urea without NBPT-DCD. Oil palm trees grew on Typic Dystrudept soil. The plants received 2.20 kg of urea treatment per plant. The researchers combined Urea with NBPT-DCD. These trees had better outcomes than others. They had less N volatilization and better N absorption. They also had higher fresh fruit bunch productivity. The others received N fertilization but not NBPT-DCD.

Analisis Beberapa Sifat Fisik Tanah Pada Tanaman Kelapa Sawit Di Desa Kuala Behe Kecamatan Kuala Behe Kabupaten Landak

<p><em>This land suitability evaluation is basically used to determine the level of suitability of a plot of land for a particular use. Kuala Behe Village currently has quite good potential in developing large areas of community oil palm plantations. The aim of this research is to analyze several soil physical properties of oil palm plants in Kuala Behe Village, Kuala Behe District, Landak Regency and provide management recommendations. The method used in this research is land surveying and mapping. The research begins with a preliminary survey of the research location, then continues with making a map of observation points determined based on the distribution of land unit maps obtained from the overlay or overlap of administrative maps, slope class maps and soil type maps with reference to the physiographic survey method. The research location has an area of 120 ha consisting of 6 land units, then continued with carrying out activities in the field (observing the physical properties of the soil and taking soil samples according to the coordinate points that have been obtained). The analysis results showed that the dominant texture was clay with a medium texture class, the effective depth of the soil was included in the deep criteria, had good drainage, very deep sulfidic hazards, light erosion and no threat of flooding. The research location has 2 types of soil, namely Typic Dystrudepts and Fluventic Dystrudepts which are classified into 6 land units, namely land units with a total area of approximately 120 ha. Improvement efforts can be made by constructing drainage channels, constructing contour terraces and planting ground cover plants.</em></p>

Impacts of Land Use Changes on Soil Functions and Water Security: Insights from a Three-Year-Long Study in the Cantareira System, Southeast of Brazil

Maintaining soil functions is crucial for human well-being, but there is a lack of integration between soil, water security, ecosystem services, and climate change. To bridge this knowledge gap and address erosion-induced soil and water losses and considering intrinsic impacts of soil structure, a three-year-long study was conducted focused on three dominant soil types (Typic Hapludult, Typic Dystrudept, and Typic Usthortent) combined with different land uses (native forest, eucalyptus plantation, rotational grazing, and extensive grazing) in a critical water supply region for the São Paulo metropolitan area in Southeastern Brazil. Surface runoff, evaluated for erosion resistance, was measured using the Cornell infiltrometer, and soil electrical resistivity tomography estimated soil water content to a depth of 1.5 m for groundwater recharge analysis. Soil hydraulic properties were also measured. The results revealed that native forest soils had higher hydraulic conductivity, particularly in the surface layer, compared to eucalyptus and pastures. Native forests in Typic Hapludult showed a higher runoff rate (200 to 250 mm h−1) due to a naturally dense subsoil layer that negatively impacted water infiltration and recharge with a high erosion potential, therefore reducing the amount of water stored. Typic Usthortent maintained a higher soil water content in pastures than in other land uses and also showed a low rate of water infiltration, resulting in perched water in the surface layer. In Typic Dystrudept, the native forest presented higher hydraulic conductivity (0–5 cm: 115.9 cm h−1) than eucalyptus (0–5 cm: 36.4 cm h−1), rotational grazing (0–5 cm: 19.4 cm h−1), and extensive grazing (0–5 cm: 2.6 cm h−1), but there were no significant differences in soil water content among land uses. This work illustrates the crucial role of native forests in affecting deep water recharge, reducing the soil surface erosion, mainly in soils without naturally subsoil layer, maintaining recharge potential. For Ultisols, pastures preserved soil structure and are therefore less impacted by soil management. With these results, a contribution is made to soil and water conservation, providing support for sustainable management practices in erosion-prone areas.

Interactions between land use and soil type drive soil functions, highlighting water recharge potential, in the Cantareira System, Southeast of Brazil

Most of the soil quality assessment protocols are focused on crop production and conservation management, while studies on vital soil functions, such as water recharge potential, should be incorporated into the monitoring of impacts on environmental quality. Our objective was to evaluate, through the Nexus approach, how dynamic (land use and management) and inherent (soil type) factors impact soil physical properties and processes that drive water recharge potential, biomass production, and water erosion in the Cantareira System, Brazil. The assessment considered three soils (Typic Hapludult, Typic Dystrudept, and Typic Usthortent) and four land uses (native forest, rotational grazing, extensive grazing, and eucalyptus), which constitute the main soils and land uses in the Cantareira System region. Representative soil samples were collected at 0–5 and 30–35 cm depth and analyzed for several soil physical quality indicators, which were used to calculate a Soil Physical Quality Index based on soil functions. Converting the native forest to eucalyptus and pasture reduced the overall soil physical quality and water recharge potential. The groundwater recharge potential function in the topsoil has the highest score of 0.72 for Typic Dystrudept in native forest contrasting with 0.16 for extensive pasture. Typic Dystrudept obtained the highest value of the SPQI value (0–5 cm: 0.85; 30–35 cm: 0.90) for native forests when compared to Typic Hapludult (0–5 cm: 0.76; 30–35 cm: 0.57) and Typic Usthortent (0–5 cm: 0.75; 30–35 cm: 0.72). Our findings sustain that land use effects on soil functions depends on soil type. Inclusion of soil type into the Nexus approach increases the understanding of natural resources and derived benefits of water, energy and food in the Cantareira System.

Classification of Soil Distribution on the Island of Saparua Based on the Soil Classification System National and the Equivalent to Soil Taxonomy

This research aims to classify the distribution of soils on Saparua Island, Central Maluku Regency, based on the Subardja, D, et al, (2016) and soil taxonomy (SSS, 2022). The benefit of this research is to find out the distribution of soils on Saparua Island to support the regional development plan. The method used is the survey method, with a semi-detailed survey level of a 1:50,000 scale. The pattern of the approach used is a physiographic analysis approach to landscapes, in which the research area is divided into terrestrial units based on the similarity of the properties of the variables that influence soil formation. The base map used in this study is a land unit map with a scale of 1:50,000. The results showed that the factors and processes involved in soil formation in the study area were parent material and topography, leaching, and eluviation processes. The soils found consisted of seven types of soil with 11 subgroups, namely: Regosol Eutric (Typic Udipsamments and Lithic Udipsamments), Litosol (Lithic Udorthents), Kambisol Distrik (Typic Dystrudepts), Kambisol Litik (Lithic Eutrudepts), Gleisol Eutrik (Typic Endoaquents and Aquic Eutrudepts), Gleisol Distrik (Typic Haplaquepts), Podsolik Kandik (Typic Hapludults and Typic Kandik), and Organosol Hemik (Hydric Tropohemists) were also found.

Effects of biochar and wood ash amendments in the soil-water-plant environment of two temperate forest plantations

Forest biomass is considered an alternative to fossil fuels in energy production, as part of global strategies for climate change mitigation. Application of by-products such as wood ash (WA) and biochar (BC) to soil could replace the nutrients removed by tree harvesting and could also increase soil carbon stocks. However, the extent to which these amendments can provide benefits depends on how the by-products interact with the soil-water-plant system. We studied the short-term responses of WA and BC application in two different mineral soil-water-plant systems in temperate forests: A. Typic Udorthent (TU) with mature Pinus radiata; B. Typic Dystrudept (TD) with young Quercus pyrenaica, to test the following hypotheses: (1) the application of WA and BC will increase nutrient uptake by plants, but (2) these products could induce toxicity in the soil-water-plant system, and (3) in case of no toxicity, plant biomass growth in these temperate forest soils will increase due to increased plant nutrient uptake. Biochar was applied at rates of 3.5, 10, and 20 Mg ha–1 and WA at rates of 1.5, 4.5, and 9 Mg ha–1 (calcium equivalent). A nitrogen enriched treatment was applied with the intermediate doses. Ecotoxicity testing indicated that WA and BC were not toxic, although Ni uptake increased in biomass of the TU after BC + N application. BC increased SOC stocks of both sites, depending on treatment. In TD BC increased K uptake by plants, but did not increase biomass. In summary, this study shows that the application of BC and WA had different effects on the soil -water-plant system in two different forest soils. This difference was attributed to (i) the soil characteristics, (ii) the application rates and (iii) whether or not nitrogen was applied. Long-term field experiments are required to test the performance and potential toxicity of these by-products as soil enhancers.

Improving Selected Chemical Properties of a Paddy Soil in Sabah Amended with Calcium Silicate: A Laboratory Incubation Study

In Malaysia, the main constraints of rice yield and productivity are infertile soils and poor management practices because these soils are characterized by low pH, low nutrient availability, low organic matter, and high exchangeable Al and Fe ions, due to high rainfall and hot temperatures. Thus, an incubation study was conducted to determine the optimum amount of calcium silicate (HmbG brand) to improve the soil pH, electrical conductivity (EC), exchangeable Al, available P, and cation exchange capacity (CEC) of a paddy soil in Sabah, Malaysia. The Kelawat series (Typic Dystrudept) soil was incubated with calcium silicate at the application rates of 0 (T1), 1 (T2), 2 (T3), and 3 t ha−1 (T4) using a Completely Randomized Design (CRD) in triplicates for 30, 60, 90, and 120 days. The calcium silicate used significantly improved soil pH because of the release of SiO44− and Ca2+ ions, which neutralized and immobilized H+ ions. Furthermore, the neutralizing effects of the amendment impeded Al hydrolysis by up to 57.4% and this resulted in an increase in the available P in the soil by 31.26% to 50.64%. The increased availability of P in the soil was also due to the high affinity of SiO44− to desorb P from soil minerals and it is believed that SiO44− can temporarily adsorb exchangeable base cations such as K+, Ca2+, Mg2+, and Na+. Moreover, applying calcium silicate at 3 t ha−1 improved soil CEC by up to 54.84% compared to that of untreated soils (T1) because of increased pH and the number of negatively charged sites. The most suitable application rate of the calcium silicate was found to be 3 t ha−1 (T4). These findings suggest that calcium silicate can improve soil productivity and agronomic efficiency in rice farming. Greenhouse and field trials are necessary to ascertain the effects of the recommended treatments of this incubation study on soil productivity, rice growth, and yield.

Morphological characteristics and classification of inceptisol in Mamuju regency, West Sulawesi

Soil morphology provide overview the evolution in the soil body through description and interpretation of soil profile properties as initial information in classifying soil. The research purpose is to determine the morphological characteristics and soil classification of Inceptisols in four study profiles: Kalonding, Batu Papan, Pepalang and Batu Ampat, in Mamuju regency, West Sulawesi. The research method used is descriptive qualitative exploration by survey in the field and soil analysis in the laboratory. The results showed that the dominant texture was clay in all soil profiles with a low silt/clay ratio. This was related to the high intensity of weathering due to high rainfall and easily weathered host rock and relatively high content of resistant minerals. Other chemical properties such as pH, N-total, cation exchange capacity, base saturation, exchangeable bases (Ca, Mg, K, Na) and P-available are generally low with a relatively constant distribution pattern with increasing depth. Soils are classified into the order of inceptisols in all soil profiles because they have a cambic sub-horizon resulting from physical alteration, chemical transformation or a combination of these processes. The hicks humidity regime so that the sub-order category is named udepts. The temperature regime includes Isohipthermic so that it is categorized into the Great Group Dystrudepts and the Typic Dystrudepts sub-group for the Study Profile of Batu Papan, Pepalang and Batu Ampat, while for the Profile of the Kalonding study is Lithic Dystrudepts.

QUANTITATIVE PARAMETERS OF FLORAL STEMS OF GLADIOLUS PLANTS GROWN UNDER MINIMUM TILLAGE SYSTEM IN SANTA CATARINA, BRAZIL

ABSTRACT The objective of this work was to characterize the commercial quantitative standards of floral stems of gladiolus plants grown under minimum tillage and conventional systems in two harvest seasons in the state of Santa Catarina, Brazil. Experiments were conducted in locations with subtropical climate using soils classified as Typic Dystrudept (Cambissolo) and Typic Hapludox (Nitossolo). Gladiolus plants were grown in beds with intensive soil turning, and under minimum tillage system, in which soil turning was done only in the planting rows. Plants of the cultivars Red Beauty and White Goddess were evaluated in two harvest seasons, Mothers' Day, and Valentine's Day. A completely randomized experimental design with 12 replications was used; the treatments consisted of two harvest seasons and two soil management systems. The flower stem and inflorescence lengths, stem thickness, and number of florets were measured when the plants were at the harvest point to characterize their commercial quantitative standards. These data were used to distribute the stems into four classes (75, 90, 110 and non-marketable). The stem standard of gladiolus plants grown under minimum tillage system and the edaphoclimatic conditions of the state of Santa Catarina in the Mother's Day harvest met the flower market requirements, with most stems classified into the classes 90 and 110. Therefore, gladiolus plants can be grown under minimum tillage system without affecting the flower stem development. This work is the first step to promote the growth of flowers under a conservationist perspective, focused on a more sustainable agriculture.

The Rapid Method of Soil Identification Based on Remote Sensing and Geographic Information Systems (Case Study of Moramo Watershed)

The field-tested samples are done by stratified random sampling. Soil classification was obtained through observation of field profile morphology and soil analysis in the laboratory followed by supporting data such as temperature and rainfall. The Moramo River Basin (DAS) was used as the location of the case study in this experiment by observing 13 soil profiles. Soil properties and characteristics were observed for soil texture, clay mineral, soil pH (H2O and KCl), soil cation, saturation bases, and C-organic. The soil naming was done to subgroup category based on Soil Taxonomy System in 2010 and paired with the land classification system of Soil Research Center in 1983, and WRB-FAO in 2006. The result showed that the accuracy of landform interpretation 89.6%, rocks 92.19%, accuracy of land use interpretation 90.63%, and accuracy of soil mapping 90.00%, so that the image ALOS AVNIR-2 can be utilized well to obtain parameter of the land unit for land mapping. The result of image data processing through RGB 341 composite image showed a high unidirectional frequency filter, histogram equalization, and analyzed with Geographic Information System, 15 units of landform, five-rock units. nine land-use units and 11 sub-soil sub-groups were obtained. The results of the soil classification in the Moramo Watershed (DAS) region in the subgroup category obtained 11 subgroups of land consisting of Lithic Udorthents, Typic Udifluvents, Aeric Endoaquents, Typic Fluvaquents, Typic Dystrudepts, Typic Eutrudepts, Ruptic-Alfic Eutrudepts, Lithic Dystrudepts, Oxyaquic Eutrudepts, Fluvaquentic Epiaquepts, Typic Endoaquepts.

Analysis of soil-forming factors and soil classification using soil taxonomy system: A case study of Baraka District, Enrekang Regency

The difference in the soil-forming factors can affect the nature of the soil formed. The method was used in this research is quantitative descriptive based on primary and secondary data. The field survey was conducted using the random stratified method at 15 soil profile divided into four north-south transects. The determination of soil characteristics value were adjusted by the Soil Survey Laboratory Manual method, while the determination of dominant soil minerals used the Fourier Transform Infra-Red (FTIR). Determination of soil type used the soil taxonomy system, which refers to the 12th edition of the soil taxonomy key book. The results of the study showed that there are two soil orders in the Baraka district, Enrekang Regency that is Alfisols and Inceptisols. Alfisols was found in the six soil profile that classified as Typic Paleustalfs (subgroup) mixed family of Isohypethemic Typic Paleustalfs, Kaolinitic with Isohypethemic Typic Paleustalfs, while Inceptisol was found in the nine soil profile that classified as Lithic Haplustepts, Dystic Haplustepts, Typic Dystrudepts and on the family category that is clay mixture Isohypethemic Typic Dystrustepts, clay mixture Isohypethemic Dystric Haplustepts, clay mixture Isohypethemic Lithic Haplustepts, Carbonatic compound Isohypethemic Dystric Haplustepts. The results of this research also indicate that the dominant soil-forming factors in the Baraka District, Enrekang Regency are the parent material, vegetation, and slopes.

Phosphorus use in soybean in integrated production system under anticipation of phosphate fertilization

Integrated crop-livestock system (ICLS), when well-managed, contributes to the maintenance of soil fertility and crop development. Practices aimed at efficiency of phosphorus use can result in economic and environmental benefits. Thus, the anticipation of phosphate fertilization may be a viable strategy for soybean crop. The objective of this study was to determine the yield, accumulation of P and P use efficiency (PUE) on the dry biomass and grains of the soybean crop, submitted to doses and sources of P, applied annually on soil surface, at the time of sowing of the winter crop. The experiment was started in 2009, in Castro-PR, under a Typic Dystrudept. The experimental design was completely randomized complete blocks, in an incomplete factorial scheme (3x3+1) with four replications. The treatments consisted of four doses (0, 60, 120 and 180 kg ha -1 of total P 2 O 5 ) and three sources (triple superphosphate, rock phosphate – Arad and magnesium thermophosphate) of P. There were no interactions between P sources and doses for the attributes: grain yield (GY), shoot dry matter (SDM), weight of thousand seeds (WTS), P accumulation in soybean (PAS), P concentration in soybean grains (PCSG), PUE and P in residual dry mass (PRDM). Linear increases were observed in GY, SDM, WTS, PCSG and PRDM and quadratic increases in PAS and PUE. The sources of P employed in this study did not change GY, SDM, TSW, PAS, PCSG, PUE and PRDM.

Stocks and Distribution of Soil Carbon, Nitrogen, Phosphorus and Sulfur in an Integrated Crop-Livestock System Treated with Phosphates

Abstract Conservation agriculture practices can contribute to changes in soil nutrient dynamics over time. This experiment evaluated the changes in total stocks and distribution of carbon, nitrogen, phosphorus and sulfur concentrations in soil, during 60 months, in an integrated crop-livestock system (ICLS) due to anticipated fertilization of sources and doses phosphates applied in soil surface. The experiment was conducted over a period of five years, under Typic Dystrudept, using a randomized block design, in an incomplete factorial scheme (3×3+1), with four replications. Treatments consisted of three sources of P [triple superphosphate (TSP), rock phosphate - Arad (RP) and magnesium thermophosphate (MTP)], along with four doses of P (0, 60, 120 and 180 kg ha-1 P2O5 total). Samples of soil were collected in 0-5, 5-10, 10-15, 15-20 and 20-30 cm layers at 24, 36, 48 and 60 months after beggining of experiment where the following chemical attributes were evaluated: (i) total organic carbon (TOC); (ii) total nitrogen Kjeldahl (TNK); (iii) available P by ion exchange resin method (P-IER); and (iv) available S-SO4 2-. The ICLS conditions provided increased total stocks and concentrations of TOC, TNK, P-IER and S-SO4 2- over time. The applications of different phosphates had no influence on soil TOC concentrations during the five years of experimentation. The concentrations of TNK, P-IER and S-SO4 2- showed an increase in different layers of soil, with the application of sources and doses of P. The P fertilization practice that was anticipated can consist of an efficient management of soil fertility, using properly managed conservation systems.

BIOMASSA HIJAUAN Mucuna bracteata DAN PENGARUHNYA TERHADAP KADAR N TANAH DI PERKEBUNAN KELAPA SAWIT

Mucuna bracteata is one of the legume cover crop that is usually used in oil palm and rubber plantations. In general, legume cover crop are planted during the preparation / after land clearing when the oil palm are planted, Mucuna bracteata has covered the planting area. Mucuna bracteata growth conditions will affect soil biological properties, namely organic nutrient content, C/N balance, microbial population and macro-fauna activity. This study aimed to describe the soil and Mucuna bracteata plants in the phase of oil palm plants. The study was conducted in April - June 2019 in the area of ​​TBM 3 oil palm plantations in 2 locations, namely Pabatu Plantation and Tinjowan Plantation. Soil types in Pabatu Plantation are typic dystrudepts (Reddish Brown Podsolik) and in Tinjowan Plantation the type of soil is typic hapludults (Yellowish Red Podsolik) and some typic paleudults (Yellow Podsolik). This study used a descriptive design that describes the growth character / biomass of Mucuna bracteata on TBM 3 oil palm plantations. The results of this study are the fresh biomass of Mucuna bracteata in Pabatu Plantation is 43,260 kg / ha and Tinjowan Plantation is 34,146 kg / ha (79%) and dry biomass is 13,943 kg / ha in Pabatu Plantation and 12,705 kg / ha in Tinjowan Plantation. The levels of N leaves of Mucuna bracteata are in the high category. Soil organic matter content and total N in Pabatu and Tinjowan Plantation are in the low category.

Digital soil mapping including additional point sampling in Posses ecosystem services pilot watershed, southeastern Brazil

This study aimed to evaluate the performance of three spatial association models used in digital soil mapping and the effects of additional point sampling in a steep-slope watershed (1,200 ha). A soil survey was carried out and 74 soil profiles were analyzed. The tested models were: Multinomial logistic regression (MLR), C5 decision tree (C5-DT) and Random forest (RF). In order to reduce the effects of an imbalanced dataset on the accuracy of the tested models, additional sampling retrieved by photointerpretation was necessary. Accuracy assessment was based on aggregated data from a proportional 5-fold cross-validation procedure. Extrapolation assessment was based on the multivariate environmental similarity surface (MESS). The RF model including additional sampling (RF*) showed the best performance among the tested models (overall accuracy = 49%, kappa index = 0.33). The RF* allowed to link soil mapping units (SMU) and, in the case of less-common soil classes in the watershed, to set specific conditions of occurrence on the space of terrain-attributes. MESS analysis showed reliable outputs for 82.5% of the watershed. SMU distribution across the watershed was: Typic Rhodudult (56%), Typic Hapludult* (13%), Typic Dystrudept (10%), Typic Endoaquent + Fluventic Dystrudept (10%), Typic Hapludult (9.5%) and Rhodic Hapludox + Typic Hapludox (2%).

EFFECT OF SOIL WATER DEFICITS ON ANNUAL FRESH FRUIT BUNCH PRODUCTION IN CENTRAL KALIMANTAN

The soil water deficits have an after-effect over the time lagged fruiting activities of palms, which subsequently affects the annual fresh fruit bunch (FFB) production in the oil palm plantation. Field data from 2014 to 2018 in a reasonably well managed oil palm estate with three soils of the greater groups of Typic Dystrudept (lnceptisol), Typic Haplohumod (Spodosol) and Typic Haplohemist (Histosol) were analysed. The palms were planted in the years 2004 and 2005, and were producing FFB at its prime plateau age of yield life cycle. The amount of monthly water deficits that results in single or multiple fruiting activities responded quadratically to subsequent annual FFB production in all three soils. With two consecutive total soil water deficits in the years 2014 and 2015, the multiple time lagged fruiting activities from bunch failure to sex differentiation with change in sex ratio favouring male inflorescences resulted in reduced yield in 2016 in all three soils. Typic Haplohumod soils being sandy achieved the lowest yield in 2016. The palms planted on Typic Haplohemist showed rapid decline in crop with the slightest water deficit. The soil derived from Typic Dystrudept gave relatively high FFB production at low water deficit. Keywords: Water deficit, fruiting activity, fresh fruit bunch production, El nino, drought.

Tropical Soil Toposequence Characterization via pXRF Spectrometry

Variability of elemental composition in a toposequence of quartzite‐derived soils in a tropical environment was evaluated via portable x‐ray fluorescence (pXRF) spectrometry. The toposequence featured different degrees of weathering and variable soil formation processes. Specifically, this study aimed to: (i) use elemental composition obtained through pXRF as a tool to investigate the degrees of weathering–leaching and pedogenic processes; and (ii) correlate elemental data with physicochemical properties of soils. Four soil profiles (Lithic Ustorthent, Typic Ustorthent, Typic Dystrudept, and Xanthic Hapludox) were described and sampled. Laboratory analysis for soil physicochemical characterization and pXRF were performed. Soils featured high contents of SiO2 due to the predominance of quartz in the rock. However, pXRF analysis revealed that the soils showed a decrease in such content with depth. Potassium contents tended to be greater in the C horizons since they are less weathered and retained greater amounts of K‐bearing minerals, such as muscovite. Al, Fe, Ca, Ti, Cu, and Sr increased their contents with increasing clay content in soils, while Zr generally remained stable. Ba was leached out of soils during weathering. Both CaO and Sr were positively correlated with exchangeable contents of Ca2+ and Mg2+, base saturation, pH, and cation exchange capacity, while inversely correlated to Al3+ saturation. Fe, Al, Ti, Ca, K, Cu, Rb, and Zr accumulated in soil in comparison with the parent material. Variability of elemental contents in soils with differential degrees of weathering–leaching can be easily accessed with pXRF and such data correlate well with several soil physicochemical properties.Core Ideas Toposequence of quartzite‐derived soils variability assessed by pXRF. Soils presented varying weathering degrees, from Entisols to Oxisols. pXRF elemental data correlated well with soil physical and chemical properties. Soil mineralogy and pXRF data elucidated soils variability with weathering. Al, Fe, Ca, Ti, Cu, and Sr increased with increasing clay content.