Tropical Soils

A Manutenção da Fertilidade do Solo em Sistemas Manejados na Amazônia. LBA, INPA, Manaus. 32 pp. URL: http://lba.daac.ornl.gov/amazonia_global_change/20_ A%20Manutencao_Fertilidade_Luizao.pdf This is a translation. Please cite the original article:

Soil fertility decline is perceived to be widespread in the upland soils of the tropics, particularly in sub‐Saharan Africa. Most studies have used nutrient balances to assess the degree and extent of nutrient depletion; these have created awareness but suffer methodological problems as several of the nutrient flows and stocks are not measured. This chapter focuses on the assessment of soil fertility decline using soil chemical data (pH, organic C, total N, available P, cation exchange capacity (CEC), and exchangeable cations) that are routinely collected in soil surveys or for the assessment of fertilizer recommendations. Soil fertility decline can be assessed using a set of properties from different periods at the same site or from different land‐use systems with the same soils. The former is easier to interpret; the latter can be rapidly collected but differences may be due to inherent differences and not have resulted from soil management. This study provides an analytical framework for the assessment of soil fertility decline and shows pitfalls and how they should be handled. Boundary conditions are presented that could be used in future studies on soil fertility management and crop productivity in the tropics.

Abstract: The aim of this research is to evaluate transport of pollutants from a sanitary landfill leachate through a Brazilian lateritic soil by two methods: laboratory tests and analysis of field contamination.
In Botucatu Sanitary Landfill, leachate stored in an unlined pond infiltrated into the subsoil for 15 years. Samples of the subjacent soil, a porous clayey sand, were collected in three profiles located inside the area of the leachate pond at the following depths: surface, 0.25 m, 0.50 m, 1.00 m, 2.00 m and 4.00 m. The investigated pollutants were arsenic, cadmium, chloride, cooper, iron, lead, manganese, nickel, Kjeldahl nitrogen, total organic carbon (TOC) and zinc. 
The hydraulic conductivity measured in undisturbed and uncontaminated samples of the local soil, around 10-6 m/s, is significantly influenced by the applied hydraulic gradient and the percolation duration. When leachate substituted water as percolation fluid, the hydraulic conductivity decreased to values between 10-8 and 10-6 m/s depending on the hydraulic gradient.
Chemical analysis of contaminated samples showed that concentrations of the researched elements in the subsoil were lower than legal maximum contamination limits established by the environmental agency of São Paulo state, in spite of the fact that the local soil is porous and has high hydraulic conductivity. On the other hand, chloride and Kjeldahl nitrogen, pollutants for which there are no legal limits, were found in concentrations much higher than background values, and in some samples even higher than those measured in the leachate sludge deposited in the bottom of the storage pond.

Resumo: Esta dissertação de mestrado tem como objetivo principal avaliar o transporte de poluentes de um lixiviado real de aterro sanitário em um solo laterítico do estado de São Paulo. A pesquisa objetiva também comparar dois métodos de avaliação de transporte de poluentes: ensaios laboratoriais e análise de dados de contaminação de campo.
No aterro sanitário de Botucatu houve, comprovadamente, percolação do lixiviado pelo subsolo durante aproximadamente 15 anos, sob uma lagoa de acumulação de lixiviado sem revestimento de fundo. Foram coletadas amostras de solo subjacente à lagoa, uma areia argilosa, em três perfis verticais na superfície e nas profundidades de 0,25 m, 0,50 m, 1,00 m, 2,00 m e 4,00 m. Os poluentes investigados foram: arsênio, cádmio, carbono orgânico total (COT), chumbo, cloreto, cobre, cromo, ferro, manganês, níquel, nitrogênio Kjeldahl total (NKT) e zinco.
Amostras indeformadas do solo local não contaminado foram também coletadas para ensaios de permeabilidade à água e ao lixiviado, assim como para ensaios de coluna. A condutividade hidráulica do solo é da ordem de 10-6 m/s, porém significativamente influenciada pelo gradiente hidráulico aplicado e pela duração da percolação. A condutividade hidráulica diminuiu com a percolação de lixiviado para ordens de grandeza entre 10-8 e 10-6 m/s, dependendo do gradiente hidráulico. Os ensaios de coluna mostraram concentrações efluentes dos elementos pesquisados superiores às afluentes, impossibilitando a obtenção de parâmetros de transporte de poluentes.
A análise das amostras contaminadas coletadas in situ mostrou que, embora o solo local seja poroso e apresente alta permeabilidade, as concentrações dos elementos estudados eram inferiores aos limites legais de contaminação do órgão de controle ambiental estadual. O cloreto e o nitrogênio, para os quais não há limites legais, apresentaram-se no subsolo em concentrações elevadas, superiores às concentrações no solo natural e, em algumas amostras, às do lodo depositado no fundo da lagoa.

The construction of pavement structures and the reinforcement of subgrade soils must be preceded by accurate characterization of pavement materials and soils. The behavior of soils can vary from point to point, even if the soils have the same genetic origin. The drainage condition of the subsoil can modify the characteristics of its mechanical behavior. Thus, the success in the use of soils as a construction material requires a great number of laboratory tests, significant time, and adequate financial resources. These factors and low costs associated with abundantly available soil deposits allow the designers to optimize the management of highway construction projects. A rapid methodology for classifying tropical soils in accordance with the MCT (Miniature, Compacted, Tropical classification) is described to fill the gap in geotechnical investigation of soils used for road construction. This paper presents the MCT classification of tropical soils and practical examples of its use on highway construction projects in the state of São Paulo in Brazil. Considerable time and cost savings are achieved by implementing the rapid disk method of the MCT classification to characterize tropical soils.

Compacted tropical soils have great potential to be used in barriers, once some technical issues are correctly addressed, including low hydraulic conductivity and compatibility to the disposed fluids. This paper involves a laboratorial study of the hydraulic conductivity of mixtures of a tropical soil sample and bentonite and also their compatibility to different chemical solutions. The experimental program consisted of (1) sample characterization, (2) hydraulic conductivity determination using a triaxial cell, and (3) compatibility assessment with different chemical solutions (HNO 3 , NaOH, NaCl, and ethanol) using the modified Atterberg Limits. The characterization results revealed important changes in the index properties of the tropical soil sample as the result of the bentonite addition, especially in the plasticity, cation exchange capacity and free swelling. The hydraulic conductivity, in turn, experimented significant decreasing as the proportions of bentonite and confining pressure increased. The compatibility results showed a significant reduction in the plasticity of the samples when subjected to the chemical solutions, especially for the salt solution. In general terms, the addition of bentonite reduced the compatibility of the samples.

In Malaysia, slope assessment systems (SAS) are widely used in assessing the instability of slopes or the probability of occurrence and likely severity of landslides. These SAS can be derived based on either one particular approach or combination of several approaches of landslide assessments and prediction. This paper overviews five slope assessment systems (SAS) developed in Malaysia for predicting landslide for large-scale assessments. They are the Slope Maintenance System (SMS), Slope Priority Ranking System (SPRS), Slope Information Management System (SIMS), the Slope Management and Risk Tracking System (SMART), and the Landslide Hazard and Risk Assessment (LHRA). An attempt is made to evaluate the accuracy of these SAS in predicting landslides based on slope inventory data from 139 cut slopes in granitic formations, and 47 cut slopes in meta-sediment formations, which are the two most common rock/soil formations found in West Malaysia. Based on this study, it was found that none of the existing SAS is satisfactory for predicting landslides of cut slopes in granitic formations, for various reasons such as the use of a hazard score developed from another country, an insufficient data base, an oversimplified approach, and the use of data base derived from different rock/soil formations. However for the case of cut slopes in meta-sediment, the Slope Management and Risk Tracking System (SMART) was found to be satisfactory with a 90% prediction accuracy. The current database of SMART is largely based on meta-sediment formations from the Kundusang area of Sabah, East Malaysia.

This study characterized the morphological, physical and chemical attributes of sandstone-derived soils at the Cerrado of the Piauí State, Brazil, in order to identify evolutionary standards. The study was carried out with five representative soil profiles identified as P1-RY (Typical Flavic Psychotic Neosol - Aquents), P2-PA (Typical Dystrophic Yellow Argisol - Alfisol), P3-RL (Fragmentary Litholic Distrophic Neosol - Psammenit), P4-RQ (Typical Ortic Quartzenetic Neosol - Orthents) and P5-PV (Typical Dystrophic Red Argisol - Ultisol). Soil samples were submitted laboratory analysis described morphologically. In general, the soils presented high sand content, low pH, low content of exchangeable bases and low cation exchange capacity (CEC). Organic matter governed the CEC in most cases, suggesting dependence of organic matter in the supply of charges. These soils showed a low degree of weathering, but with iron of high crystallinity. Thus, the relief and the parent material are the major important soil-forming factors at the Cerrado of the Piauí State. Moreover, these soils are young, with the soils from the Piauí Formation being more evolved. However, the sandstones from the Canindé Group apparently are providing lithological secondary minerals for the soil.

Iron oxide minerals in soils provide valuable insights into pedogenic processes. A wealth of such information has been obtained by rock magnetic investigations on temperate soils but similar studies on tropical soils are rare. Here, we report rock magnetic data on pristine soil profiles and surficial soils from five catchments in the tropical southern India and throw light on the pedogenic processes. We ruled out contributions from greigite, bacterial magnetite and anthropogenic sources; hence, the magnetic signal is mainly from the catchment, principally pedogenic and, thus, has a climatic signature embedded in it. The Pookot profile from a high rainfall (~4000 mm/year) region does not exhibit any magnetic enhancement at the surface. In fact, there is hardly any difference between surface and sub-surface samples, which reflects on its deeply weathered nature as a result of the high rainfall. The Shantisagara profile exhibits lessivage of magnetic minerals, resulting in a thick magnetically enhanced zone. It shows the highest χ lf values among the five profiles studied. The Thimmannanayakanakere (TK) and Ayyanakere (AK) soil profiles do not exhibit any magnetic enhancement of top-soil. In fact, χ lf values increase towards the profile-bottom, suggesting top-soil erosion, besides contribution of magnetic minerals from parent rocks. In the TK profile, there is a clear distinction between surface and sub-surface samples, the former being magnetically coarser grained. The Kurburukere profile exhibits moderate to strong χ lf values and a mild magnetic enhancement at the surface.The data would be useful for establishing soil-sediment linkages for paleoclimatic studies of lake sediments.

Many of soil amendment formulations (as a biochar based) have been tested in Indonesian Soil Research Institute greenhouse experiment to improve its effectiveness in the soil, though field experiments were still needed to measure more about its effectiveness. The objectives of this research are to study biochar-based soil amendment formulation on different ways of application in improving soil properties and crop yield in upland acidic soil. The research was conducted in Taman Bogo Research Station, East Lampung during three planting seasons. It started at January 2013 and finished at January 2014. The study was arranged in a split plot design with 3 replications. The main plot was 3 types of soil amendment formula namely SP50, SP75 and KS50. The subplot was the biochar-based soil amendment application way (7.5 Mg ha-1 per planting seasons), which gradually applied to soil namely three times of 3 planting seasons (2.5-2.5- 2.5 Mg ha-1), two times of 3 planting seasons (5.0-2.5-0 Mg ...

The most principal objective of this work is a development of na active method for tropical soils identification for highway finality, according MCT classification, with a similar simplicity a manual-visual examination used for soils identification, similar as “Unified Soil Classification System”.
Through bibliografics search it was looking for to study some ones National Public Departments, concerning to soils identification, as well as its classifications and limitations it was selected by MCT methodology (Miniatura, Compactado, Tropical) wich proves be most appropriate way for this kind of soil.
An experimental search was developed since Nogami and Cozzolino (1985) looking for an active method for MCT classification for soils identification, constituted of elementaries procedures, with a simple and cheap kind of apparates, it’s based on empiricals indexes and qualitatives determinations and has a very great utility principarly respecting to lateritic behavier of soils separation from not lateritic soils, looking for a way to reduce the cost of choices study, either respecting deposits on any other alternative for roads design,
At last, it was tested 52 soils samples, whose MCT classification was known and belonging to the differents groups, taking care to include transition soils in this sample staff looking for its localization in MCT Classification Chart reaching an other group.
With the purpose to verify the results repetition, it was tried to test each sample more than a time, changing the operator, than getting an explicity chart for MCT classification.
Also, it was been realized a comparative study of the offered test (with Rigid PVC rings) and others kinds of tests employed inside HRB, USCS and MCT classification confirming that the test with rigid PCB rings reachs 20% of the cost reporting all others similars.

Biodegradation of NR latex gloves in an Oxisol in response to nitrogen (N) and phosphorus (P) application was compared with several synthetic alternatives (polychloroprene, nitrile and plasticised PVC). Pieces of glove materials placed in nylon-net mesh bags were buried for up to 40 weeks in soils within containers receiving a high -(WO mg L~! N, 150 mg L~' P) or a low -(10 mg L~', 15 mg L~! P) nutrient treatment and an unamended control Mass losses of NR glove pieces were rapid in the high-nutrient treatment compared to the low or the control treatment. The NR glove pieces retained 17.6% of its initial weight in the high-nutrient treatment at 40 weeks, whereas the synthetic materials remained intact except for plasticised PVC which retained 73.9% of its initial mass. The specific degradation rate ofNR glove pieces, expressed as mass loss per week was three times higher under a high-nutrient regime than when left to natural attenuation processes. Degradation of the NR test pieces was consistent with the drastic reduction in tensile properties, and with the higher number of bacteria, actinomycetes and fungi colonizing (he material.

Fertile dark anthrosols associated with pre-Columbian settlement across the Amazon Basin have sparked wide interest for their potential contribution to sustainable use and management of tropical soils and ecosystems.  In the Upper Xingu region of the southern Amazon, research on archaeological settlements and among contémporary descendent populations provides critical new data on the formation and use of anthrosols.  These findings provide a basis for describing the variability of soil modifications that result from diverse activities and a general model for the formation of Amazonian anthrosols.  They underscore the potential for indigenous systems of knowledge and resource management to inform efforts for conservation and sustainable development of Amazonian ecosystems.

It is generally known that zeolite has potential for heavy metal adsorption. The  objectives of this study were to synthesize and characterize zeolite ZSM-5 and to figure out the adsorption capacity of zeolite ZSM-5 for heavy metals of Cu2+, Pb2+ and Cd2+. Characterization of zeolite ZSM-5 included some variables i.e. crystal structure (XRD), morphology (SEM), specific surface area and total pore volume (N2 physisorption). Adsorption capacity of zeolite ZSM-5 was analysed using a batch system with heavy metals of Cu2+, Pb2+ and Cd2+ in various concentrations (50, 100, 150, 200 and 250 ppm) with contact times 30, 60, 90, 120 and 250 minutes. Adsorption data was calculated by Langmuir and Freundlich isotherm. The results showed that the maximum adsorption capacity of zeolite ZSM-5 against heavy metals of Pb2+, Cu2+, and Cd2+, were 74.07, 69.93 and 60.24 mg g-1, respectively. These indicated that synthetic zeolite ZSM-5 had potential to adsorb heavy metals. The results also suggested t...

ADE, a result of domestic, economic, and agricultural activities in and around human settlements, are noted for their extraordinary fertility and resilience and for the significant quantities of organic carbon, much in the form of charcoal. The deepest and most extensive areas of ADE are generally located on the bluffs of major rivers adjacent to floodplains, but significant areas of ADE have also been found in floodplains and in headwater and interfluvial areas. Our research aims to shed light on the distribution of modified soils in distinct regions of the Amazon in relation to landforms and the environment. Although research on ADE has led to a proliferation of studies on charcoal in soil management and the development of a ‘biochar’ industry that promotes the incorporation of charcoal into the soil for the dual purpose of improving fertility and sequestering carbon, there is a notable lack of research attempting to quantify the carbon over the scale of a site or region in Amazonia. We undertook this challenge in the Upper Xingu region of southeastern Amazonia in partnership with the local Kuikuro indigenous community who have shared their valuable traditional knowledge on the creation and management of ADE. We used data from over 3500 soil samples from diverse contexts, both ancient and modern, that we collected and analyzed over the past two decades for organic carbon and a range of other chemical and physical properties. Dark earth samples from profiles down to 1 m depth in archaeological sites ranged from 20% to 150% more OC than unmodified forest soil and dark earth profiles in current and historic villages ranged from 20-90% more. We used the results from soil sample transects to estimate the carbon in landuse zones within and surrounding modern, historic, and ancient settlement sites. In continuing work, we are attempting to use satellite remote sensing and artificial intelligence with ground truth data to extrapolate our results across the Upper Xingu region and beyond.

2Soils data from the 1000-km area covered by the Biological Dynamics of Forest Fragments (BDFFP) reserves (north of Manaus, Amazonas) provides detailed information of the type used in development planning, such as the economic-ecological zoning of the region now being carried out by the Brazilian government. The soil in the reserves is typical of vast areas of Brazilian Amazonia that are likely to be increasingly deforested for agriculture and ranching. These soils have low fertility, are acid and have high levels of toxic aluminum ions. They also have limitations due to topography, generally very high clay content, and low values of available water capacity. Agricultural potential is low, and the prospects for resilience are not bright given the reality of changing land-use patterns in the region. The soils under forest also give indications of the environmental impact of converting these areas to pasture and other uses, including the potential for release of greenhouse gases (whic...

Remediation methods for environmental contamination problems based on physical or chemical processes frequently present low efficiency and/or high costs. On the other hand, biological treatment is being proved to be an accessible alternative for soil and water remediation. Bioventing is commonly used for petroleum hydrocarbon (PHC) spills. This process provides better subsurface oxygenation, thus stimulating degradation by indigenous microorganisms. In Brazil, gasoline and ethanol are routinely mixed; some authors suggest that despite gasoline high degradability, its degradation in the aquifer is hindered by the presence of much rapidly degrading ethanol. The present study evaluates a bioventing treatment of a gasoline–ethanol contaminated undisturbed residual soil from Rio de Janeiro. Contamination and treatment effects were monitored by conventional microbiology methods, chemical analysis, and ground penetrating radar (GPR) measurements. Results of culturable bacterial population counts show the effect of contamination and bioventing on the microbiota of gasoline and gasoline–ethanol containing soils; however, GPR responses to these variations are not conclusive and still need to be assessed.

Timber harvesting may have significant effects on soil organic matter content through mechanical disturbance, inputs of logging slash, alterations in litter production, and leaching of dissolved organic matter, as well as the alteration of temperature and moisture regimes. To investigate the effect of post-harvest period of tree harvesting on the dynamics of soil organic matter content, surface soils (0 to 10 cm and 10 to 20 cm) were collected from intact Acacia mangium Willd. plantation (control) and from A. mangiumWilld. harvested in 2001, 2002, 2004, and 2006 in four replicates. Each replicate consisted of composited 4 subsamples. Timber harvesting reduced litter accumulation on soil surface. However, the amount of litter accumulated on soil surface increased as post-harvest period increased. Timber harvesting significantly (p<0.001) affected soil organic matter content both in 0 to 10 cm and 10 to 20 cm. The increases in soil organic matter content were significantly correlat...

This research aimed to determine site specific NPK fertilizer rates combined with rice straw compost application for rice grown on the tidal lowland. This research was conducted in a greenhouse in Indralaya, Ogan Ilir, South Sumatera in February until September 2017 using a factorial completely randomized design with two factors and three replications. The first factor was NPK fertilizer rate calculated based on the results of soil chemical analysis, consisting of five levels, namely 50% (D 1), 75% (D 2), 100% (D 3), 125% (D 4) and 150% (D 5) of the site-specific fertilizer rate. The second factor was rice straw compost rate consisting of two levels, namely 5 Mg ha-1 (J 1) and 10 Mg ha-1 (J 2). The results showed that the application of 150% NPK rate and 10 Mg ha-1 rice straw compost resulted in the best effects on the rice growth grown on the tidal lowland. The application of those fertilizer doses produced the highest maximum number of tillers and productive tillers. In this regard the doses of NPK fertilizers that should be applied are 315 kg urea ha-1 , 135 kg SP-36 ha-1 and 90 kg KCl ha-1 .

Presently, about 20% of oil palm (Elaeis guineensis Jacq) fields in Indonesia are on peat soil, in addition to that otherarea of peat soil has been conventionally used for rice field and vegetables. To elucidate the global warmingpotentials of peat soils cultivated to oil palm, vegetable or rice field, field experiment has been carried out in SouthKalimantan. Air samples were taken from rice field, oil palm and vegetable fields in weekly basis for six month periodand analyzed for concentrations of N2O, CH4 and CO2. The global warming potentials (GWP) of the three gases werecalculated by multiplying the emission of each gas with their respective mole warming potential. This step wasfollowed by the addition of the three gases’ GWP to have the total GWP. The results showed that the emissions ofgreenhouse gases from peat soils changed seasonally and varied with the crops cultivated. Oil palm has resultedthe highest GWP, mostly contributed by N2O. There was no statistical different in to...

Penelitian lapangan dan laboratorium dilakukan (1) untuk mengetahui perilaku adsorpsi fosfor (P) yang menggunakan Metode Langmuir dan hasil tebu serta P terangkut panen yang dipengaruhi oleh pupuk organik (kompos) dan anorganik dan (2) untuk mengetahui korelasi antara parameter Langmuir dan ketersediaan P atau P terangkut panen tebu. Percobaan lapangan dan laboratorium disusun dalam rancangan acak kelompok, terdiri dari lima perlakuan (A = 100% NPK, B = 100% kompos, kompos C = 100% NPK + 50% kompos, D = 50% NPK + 100%, kompos , dan E = tidak ada pupuk). Setiap perlakuan diulang tiga kali.

This research was conducted to study the population and diversity of soil and leaf litter mesofauna in arable soils under different types of vegetation and slope at the Agriculture Experimental Field (AEF) of University of Lampung. This study was designed to use the survey method. The soil and leaf litter samples were taken from different vegetation and slope classes. Observational variables included population and diversity index of soil mesofauna (H’), soil temperature, soil moisture content, soil pH, soil organic-C, soil total-N, and soil C/N ratio. The data of population distribution were presented in a boxplot diagram and the correlation between soil properties and mesofauna population or mesofauna diversity index were presented. The results showed that the most abundant soil mesofauna was observed in the plots with sugarcane vegetation, either sampled at the end of dry season (November 2015) or at the beginning of rainy season (April 2016). However, the highest number of leaf ...

Penelitian ini bertujuan untuk melakukan pengujian pupuk Organonitrofos Plus (OP) pada jagung manis (Zea mays Saccharata L.) dan pengaruhnya terhadap perubahan sifat kimia tanah Ultisols. Pupuk Organonitrofos Plus merupakan pengembangan dari pupuk Organonitrofos yang diperkaya dengan mikroba pada saat awal proses pembuatannya. Penelitian dilakukan di rumah kaca Laboratorium Pertanian Terpadu Universitas Lampung. Perlakuan yang diterapkan adalah faktorial 4 × 2 × 3 dengan 3 ulangan dalam Rancangan Acak Kelompok. Faktor pertama adalah dosis pupuk OP (0, 10, 20, 30 Mg ha-1), faktor kedua adalah dosis pupuk anorganik (tanpa pupuk anorganik dan dengan pupuk anorganik, yaitu Urea 0,44, SP-36 0,28, dan KCl 0,16 Mg ha-1), dan faktor ketiga adalah dosis biochar (0, 10, 20 Mg ha-1). Pemberian pupuk OP tunggal, pupuk anorganik, dan interaksi antara OP dan anorganik meningkatkan bobot brangkasan kering, panjang tongkol, diameter tongkol, bobot tongkol dengan kelobot, dan bobot tongkol tanpa kelobot. Pemberian pupuk OP dapat memperbaiki kesuburan tanah Ultisols dan meningkatkan produksi tanaman jagung sehingga pupuk OP dapat mengurangi pemakaian pupuk anorganik dan dapat dijadikan substitusi pupuk anorganik. Nilai RAE tertinggi ada pada perlakuan O4K2B2 (30 Mg OP ha-1 , dengan pupuk anorganik, 10 Mg biochar ha-1) yaitu sebesar 181 % diikuti O2K2B3 (10 Mg OP ha-1 , dengan pupuk anorganik, 20 Mg biochar ha-1) dengan selisih nilai RAE sebesar 0,5%. ABSTRAK This Study aimed to examine the effect of Organonitrofos Plus fertilizer (OP) on sweet corn (Zea mays Saccharata L.) and soil chemical properties of Ultisols. Organonitrofos Plus fertilizer is an enhancement of Organonitrofos fertilizer enriched with microbes at the beginning of the manufacturing process. Research was conducted in the green house of Agriculture Integrated Field Laboratory of Lampung University. Treatment applied was a factorial of 4 ×2 × 3 with three replications in a randomized block design. The first factor was the dose of OP fertilizer (0, 10, 20, 30Mg ha-1), the second factor was the dose of inorganic fertilizers (without inorganic fertilizers, and with inorganicfertilizers, namely Urea 0.44, 0.28 SP-36 and KCl 0.16 Mg ha-1), and the third factor was the dose of biochar (0, 10, 20Mg ha-1). Application of OP fertilizer, inorganic fertilizer, and the interaction between the OP and the inorganicfertilizers increased the weight of dry stover, cob length, cob diameter, cob with husk and cob without husk of corn.OP fertilizers which are applied in Ultisols can improve soil fertility and increase corn production so that OP fertilizercan lessen the use of inorganic fertilizer and can be used as a substitute for inorganic fertilizer. RAE values werehighest in treatment of O4K2B2 (30 Mg OP ha-1 , with inorganic fertilizer, 10 Mg biochar ha-1) that was equal to 181%,followed by O2K2B3 (10 Mg OP ha-1 , with inorganic fertilizer, 20 Mg biochar ha-1) with the difference in RAE valueof 0.5%.

The objectives of the research were to compare the quality of physical and chemical characteristics of the soils in the oil palm plantations applied with integrated farming system of cattle and oil palm plantation (IFSCO) and without IFSCO (non-IFSCO), as well as to evaluate the economic benefits of IFSCO application. The research was conducted in two oil palm plantations, i.e. an oil palm plantation applied with IFSCO (5 ha) and an oil palm plantation without IFSCO application (non-IFSCO) (5 ha), located in the Karya Makmur Village, Penawar Aji Subdistrict, Tulang Bawang District, Lampung, Indonesia, in June until August 2016. The research was conducted using a survey and systematic sampling methods to collect soil samples, and data from 30 farmers who applied IFSCO and other 30 farmers who applied non-IFSCO. The results showed that the application of organic fertilizer in the IFSCO field resulted in higher level of exchangeable-K, -Ca, -Mg, and -Na, cation exchange capacity (CEC),...

Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method (Sulakhudin, A Syukur, D Shiddieq and T Yuwono): In coastal sandy soil, mainly nitrogen losses due to leaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, and humic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated urea with humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare two kinds sources of humic substances (cow manure and peat) which mixed with calcium as coated urea on transformation, vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5% and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHM) and humic-calcium from peat (UCHP) increased the N total and available N in the soil and decreased leaching loss of N from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium on incubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHM ranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between 21.44% and 23.25%, whereas for urea (control) reached 29.48%. Leaching losses of mineral N were lower when urea coated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM is better than UCHP in decreasing N leached from coastal sandy soil.

Population and diversity of arbuscular mycorrhiza fungi (AMF) are varied in the soil and influenced by biotic factors such as host plant and abiotic factors such as soil fertility, soil moisture, pH, temperature, etc. This study aimed to determine the population, diversity, and the dominant type of AMF in the rhizosphere of Kasetsart cassava clones obtained from LampungTimur and Tulang Bawang Barat Regencies, Lampung Province, Indonesia. Population of AMF was counted directly from the rhizosphere of Kasetsart cassava clones and the diversity of AMF was assesed using a pot culture experiment. The results showed that the population and the diversity of AMF in the rhizosphere of Kasetsart clone obtained from Tulang Bawang Barat was higher than that from LampungTimur. The predominant type of AMF found in the pot culture using soil samples from Lampung Timur was spore with S2 code that belongs to the genus Gigaspora and S4 code that belongs to the genus Glomus. On the other hand, the type of AMF found in the rhizosphere of soil samples from Tulang Bawang Barat was dominated by spore with S9 code that belongs to the genus Entrophospora.

The study was aimed to quantify volume of surface runoff, soil erosion and nutrient loss from the forest-agriculture landscape (forest margins) in Lore Lindu National Park Central Sulawesi. Surface runoff volume and soil erosion were measured daily on erosion plots. It was installed on several land use types i.e. forest land, maize, young cocoa, medium cocoa, old cocoa, vanilla, shrub and bush and bareland, on the soil Typic Dystrudepts with slope ± 40%. The nutrient content in surface runoff and sediments were analyzed from selected surface runoff and sediment samples. Surface runoff and soil erosion from agriculture land were respectively 2.1 to 3.4 and 3.6 to 5.8 times higher than from forest lands. Meanwhile, surface runoff and soil erosion from bareland were respectively 7.0 and 23.7 times greater than forest land respectively. Sediment nutrient contents from forest land were higher than agriculture land. In the contrary, total nutrient lost from agriculture land were higher than forest land ones. Nutrient losses carried by surface runoff were larger than those losses carried by sediments. Dissolved organic carbon (DOC) loss in surface runoff was 6,1 to 8,0 times higher than total organic carbon (TOC) loss in sediments. Likewise, nitrate (NO3-) loss in surface runoff was 1.9 to 12.1 times higher than total nitrogen (TN) in sediments as well as potassium, calcium, magnesium and sodium losses. Potassium is dominant cation loss carried by the surface runoff, while calcium is mainly carried by sediment.

A wide and deep soil profile (around 1200 cm) was observed at Ketep Park West Slope of Merbabu volcano Central Java, Indonesia to identify the soil morphology, physical and, chemical and mineralogical properties.  Results showed that several soil development processes occurred in each volcanic deposits with different characteristics.  Most soil layers met some of andic soil properties criteria such bulk density <0.9 g.cm-3, P retention of >85%, and (Alo + ½ Feo) >2.0%.  A thin melanic material showing black color layer was found at the lower part of the soil profile, i.e. in depth from 726 to 798 cm.  The dominant material in most soil layers is an allophane.  Minerals in the sand fraction were dominated by labradorite and augite, with some layers were hypersthene and green hornblende.

Tuberose (Polyanthes tuberosa L.) is a potential flowering plant that will be developed in Jatinangor, West Java, Indonesia. However, the characteristics of Typic Hapludult soil in Jatinangor , i.e. clay texture, acidic pH, and high amount of total-P but low in available-P cause the tuberose difficult to grow optimally. The aim of this study was to obtain the potential ratio of organic and inorganic fertilizer dosages for tuberose grown on Typic Hapludult. The combinations of organic and inorganic fertilizers with different ratios (0/0; 0/1; 1/0; 0.5/0.5; 0.5/1; 1/0.5; 1/1.5; 1.5/0; 1.5/0.5, and 1.5/) were applied. The application of the combination of organic and inorganic fertilizers showed positive effects on soil pH, available-P, total-P, and fresh weight of tuberose grown on Typic Hapludult. The application of 50% organic fertilizer + 50% inorganic fertilizer was an effective combination that was able to increase the fresh weight of tuberose up to 9240 g plant-1 or increasing t...

RESUMEN Por milenios los agricultores han mejorado sus cultivos utilizando la variación genética y seleccionando las mejores variedades. Hoy nos enfrentamos a un reto sin precedentes: alimentar la creciente población mundial. Así, aumentar los rendimientos de cultivos de importancia global, como la yuca, es crucial para la seguridad alimentaria. Esta raíz tropical alimenta aproximadamente 1.000 millones de personas en alrededor de 105 países en el mundo y sus productos son la tercera fuente de calorías más importante para los países del trópico. Esta planta es altamente dependiente de la asociación con hongos formadores de micorrizas arbusculares (HFMA). Estos hongos ayudan a la planta a obtener fósforo del suelo, un nutriente limitante principalmente en los suelos del trópico. Recientemente, nuestro grupo de investigación colombo-suizo, mostró que la inoculación de cultivos de yuca con Rhizophagus irregularis incrementó los rendimientos en dos localidades diferentes de Colombia. Más aún, conseguimos enormes diferencias en la productividad de la yuca, utilizando diferentes líneas genéticamente mejoradas del hongo R. irregularis, en condiciones de campo. Es improbable observar cambios tan dramáticos, en campo, en la producción de yuca, con un ciclo de mejoramiento de la planta. Así, combinando la agronomía con la biología y la genética, proponemos un cambio en el paradigma del mejoramiento vegetal, que pueda contribuir a resolver el problema de hambruna en el mundo. ABSTRACT For millennia farmers have been improving crops by using their natural genetic variation, selecting the best varieties. Today we face an unprecedented challenge to feed the growing global human population that can only be achieved with major changes in how we combine science and technology with agronomy. Cassava is globally important, annually feeding almost a billion people in 105 countries. It is an important crop for subsistence farming throughout tropical and subtropical regions for smallholder farmers, but especially in sub-Saharan Africa. Cassava is highly dependant on arbuscular mycorrhizal fungi to survive. Mycorrhizal fungi form symbioses with all our major crops. They help plants obtain phosphate from the soil; an essential nutrient that limits cassava production in the tropics. Our Colombian-swiss group have shown a significant effect of Rhizophagus irregularis inoculation on yield of cassava in field conditions in two locations in Colombia. Further, huge differences in the productivity of cassava can be achieved by inoculating it with genetically different lines of R. irregularis. The variation in cassava growth we observed is so large that it would be very unlikely in one generation of plant breeding to see similar variation in cassava growth. By combining agronomy with biology and genetics, we propose a shift in the paradigm of plant breeding that could help to solve the problem of hunger in the world.

A dissolution experiment was carried out to identify the effects of milling condition on dissolution kinetics of silicate rock fertilizers. Initially ground materials (Ø < 250 μm for basalt, dolerite, gneiss, and Ø < 150 μm for K-feldspar) were further milled with a ball mill (Spex 8000) under dry and wet conditions for 10, 60, and 120 minutes. The rock powders were dissolved in a mixture of 0.01M acetic-citric acid at a rock powder/solvent ratio of 1/1000, and the solution was agitated continuously on a rotary shaker at 25o C.  The concentrations of dissolved Na, K, Ca, Mg, Al, and Si from the milled rocks were determined at intervals from 1 hour up to 56 days. Results indicated that the relationships of quantity of dissolved rock and elemental plant nutrients (Et) with time (t) were well described by a power equation: Et = Eo + atn with reaction order (n) of 0.3 – 0.8. Milling increased quantity of total and individual dissolved element (Et ), dissolution rate (Rt), the prop...

The farmers realize that green revolution technology with high inputs is no longer sustainable. They want to move to other rice farming systems. The aim of research was to study soil chemical-physical characteristics and rice productions under  three  rice farming systems. This study was conducted in Vertisols at Sambung Macan Sub District, Sragen Regency, arranged in a randomized complete block design with three replications and as the treatments was an organic, semi organic and conventional rice systems. One kilo gram composites soil  samples of 0-20 cm in depth were collected from five random sampling points of every site and taken in March 2017, before soil preparation. Rice biomass productions namely rice grains, rice straw and rice residues were harvested in the end of June 2017. The results indicated that in organic field, the soil chemical-physical fertility was superior to that of in semi organic and conventional and semi organic system was better than conventional in terms...