The assessment of structure in tropical soils

1955 ◽  
Vol 45 (4) ◽  
pp. 401-410 ◽  
Author(s):  
H. C. Pereira
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Pore Space ◽  
Field Capacity ◽  
Tropical Soils ◽  
Soil Types ◽  
Acceptance Test ◽  
Volcanic Origin ◽  
Lateritic Clay ◽  
Wet Sieving

A comparison of methods of measuring the structural condition of cultivated surface soil was made for two important East African soil types.The soil samples were drawn from two field experiments: (i) a tillage trial in coffee on a porous red lateritic clay soil of recent volcanic origin; (ii) a rotation trial for cotton, on a red sandy lateritic loam of granitic origin.Of the measurements on soil cores, total porespace and field capacity (⅓ atmosphere) showed little change, while percolation rates, free-draining pore-space and a new rainfall acceptance test all reflected the observed field behaviour of the soils, and showed fairly close and highly significant correlation. Field sieving of dry clods gave highly significant differences in the lateritic clay, the stronger clods indicating the poorer soil condition. Drysieving for ½ mm. crumb was ineffective, as was wet-sieving after wetting under vacuum. Wetting by immersion gave some differences between treatments, but higher variability and no significant correlation with free-draining pore-space. Wetting by rainfall impact on dry crumbs gave the best wet-sieving tests on the clay soil. Different sieving techniques gave inconsistent results on the sandy soil. Crumb structure measurements are not efficient indications of structural conditions on these soil types, which are of wide occurrence in tropical countries.

scholarly journals Evaluation of cotton stalks destroyers

2013 ◽  
Vol 33 (5) ◽  
pp. 965-975 ◽  
Author(s):  
Aloisio Bianchini ◽  
Pedro H. de M. Borges
Keyword(s):  
Soil Type ◽  
Energy Demand ◽  
Crop Residues ◽  
Clay Soil ◽  
Field Capacity ◽  
Soil Types ◽  
Mechanical Destruction ◽  
Cotton Crop ◽  
Cotton Stalks ◽  
Medium Texture

The destruction of the cotton crop residues (cotton stalks) is a mandatory procedure in Brazil for prophylactic issues, but is a subject unexplored by the research and there are few studies that deal with this issue. However, this is not encouraged in recent decades, studies aimed at developing and evaluating equipment for this purpose. The present study had the objective to evaluate six methods for mechanical destruction of cotton crop residues. Each method was defined based on the principle of operation of the active parts of the equipment, which were tested in medium texture soil and in a clayey one. The variables used to evaluate the efficiency of the equipment were the regrowth rate, the theoretical field capacity and energy demand. The equipment with convergent concave disks (DCC) and flat cutters discs from manufacturer A (CPS-a) showed the best results in cotton stalks destruction in both soil types. The harrow disc (GPD) was efficient only in clay soil. It was concluded that the equipment with convergent concave disks, among those tested, was the most efficient to destroy cotton stalks, regardless of soil type, and that the harrow disc was not included among the best performers.

scholarly journals Genotypic Variation in Nutrient Uptake Requirements of Rice Using the QUEFTS Model

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Sheng Tang ◽  
Kefeng Han ◽  
Ping He ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Field Experiments ◽  
Hybrid Rice ◽  
Genotypic Variation ◽  
Tropical Soils ◽  
Study Data ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Indica Hybrid Rice ◽  
Validation Experiments

Nutrient requirements for single-season rice using the quantitative evaluation of the fertility of tropical soils (QUEFTS) model in China have been estimated in a previous study, which involved all the rice varieties; however, it is unclear whether a similar result can be obtained for different rice varieties. In this study, data were collected from field experiments conducted from 2016 to 2019 in Zhejiang Province, China. The dataset was separated into two parts: japonica/indica hybrid rice and japonica rice. To produce 1000 kg of grain, 13.5 kg N, 3.6 kg P, and 20.4 kg K were required in the above-ground plant dry matter for japonica/indica hybrid rice, and the corresponding internal efficiencies (IEs) were 74.0 kg grain per kg N, 279.1 kg grain per kg P, and 49.1 kg grain per kg K. For japonica rice, 17.6 kg N, 4.1 kg P, and 23.0 kg K were required to produce 1000 kg of grain, and the corresponding IEs were 56.8 kg grain per kg N, 244.6 kg grain per kg P, and 43.5 kg grain per kg K. Field validation experiments indicated that the QUEFTS model could be used to estimate nutrient uptake of different rice varieties. We suggest that variety should be taken into consideration when estimating nutrient uptake for rice using the QUEFTS model, which would improve this model.

scholarly journals A Long Journey of CICA-17 Quinoa Variety to Salinity Conditions in Egypt: Mineral Concentration in the Seeds

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 407
Author(s):  
Juan A. González ◽  
Leonardo Hinojosa ◽  
María I. Mercado ◽  
José-Luis Fernández-Turiel ◽  
Didier Bazile ◽  
...  
Keyword(s):  
Field Experiments ◽  
Chemical Elements ◽  
Chenopodium Quinoa ◽  
Soil Types ◽  
Arid Environments ◽  
Mineral Concentration ◽  
Marginal Lands ◽  
Promising Alternative ◽  
Pattern Distribution ◽  
Induced Changes

Quinoa may be a promising alternative solution for arid regions, and it is necessary to test yield and mineral accumulation in grains under different soil types. Field experiments with Chenopodium quinoa (cv. CICA-17) were performed in Egypt in non-saline (electrical conductivity, 1.9 dS m−1) and saline (20 dS m−1) soils. Thirty-four chemical elements were studied in these crops. Results show different yields and mineral accumulations in the grains. Potassium (K), P, Mg, Ca, Na, Mn, and Fe are the main elements occurring in the quinoa grains, but their concentrations change between both soil types. Besides, soil salinity induced changes in the mineral pattern distribution among the different grain organs. Sodium was detected in the pericarp but not in other tissues. Pericarp structure may be a shield to prevent sodium entry to the underlying tissues but not for chloride, increasing its content in saline conditions. Under saline conditions, yield decreased to near 47%, and grain sizes greater than 1.68 mm were unfavored. Quinoa may serve as a complementary crop in the marginal lands of Egypt. It has an excellent nutrition perspective due to its mineral content and has a high potential to adapt to semi-arid and arid environments.

scholarly journals Silicate fertilization of tropical soils: silicon availability and recovery index of sugarcane

2013 ◽  
Vol 37 (5) ◽  
pp. 1267-1275 ◽  
Author(s):  
Mônica Sartori de Camargo ◽  
Gabriela Rocha ◽  
Gaspar Henrique Korndörfer
Keyword(s):  
Acetic Acid ◽  
Residual Effect ◽  
Tropical Soils ◽  
Soil Types ◽  
Silicon Source ◽  
Recovery Index ◽  
Over Time

Sugarcane is considered a Si-accumulating plant, but in Brazil, where several soil types are used for cultivation, there is little information about silicon (Si) fertilization. The objectives of this study were to evaluate the silicon availability, uptake and recovery index of Si from the applied silicate on tropical soils with and without silicate fertilization, in three crops. The experiments in pots (100 L) were performed with specific Si rates (0, 185, 370 and 555 kg ha-1 Si), three soils (Quartzipsamment-Q, 6 % clay; Rhodic Hapludox-RH, 22 % clay; and Rhodic Acrudox-RA, 68 % clay), with four replications. The silicon source was Ca-Mg silicate. The same Ca and Mg quantities were applied to all pots, with lime and/or MgCl2, when necessary. Sugarcane was harvested in the plant cane and first- and second-ratoon crops. The silicon rates increased soil Si availability and Si uptake by sugarcane and had a strong residual effect. The contents of soluble Si were reduced by harvesting and increased with silicate application in the following decreasing order: Q>RH>RA. The silicate rates promoted an increase in soluble Si-acetic acid at harvest for all crops and in all soils, except RA. The amounts of Si-CaCl2 were not influenced by silicate in the ratoon crops. The plant Si uptake increased according to the Si rates and was highest in RA at all harvests. The recovery index of applied Si (RI) of sugarcane increased over time, and was highest in RA.

Investigations in crop husbandry. III. Effect of time of application of sulphate of ammonia to wheat

1936 ◽  
Vol 26 (2) ◽  
pp. 316-327 ◽  
Author(s):  
F. H. Garner ◽  
H. G. Sanders
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Foot Rot ◽  
Plant Establishment ◽  
Poor Condition ◽  
Time Of Application ◽  
Gravelly Soil ◽  
Heavy Clay ◽  
Crop Husbandry

1. Over a period of six years seven field experiments were carried out to study the effect of the time of application of sulphate of ammonia to autumn-sown wheat.2. Three experiments were located on light gravelly soil which had been farmed highly for some years, and in those three cases sulphate of ammonia decreased yield, irrespective of time of application; the reduction in yield was of the order of 10 per cent. and is ascribed to more lodging and greater incidence of “foot-rot”.3. Three experiments were located on heavy clay soil in poor condition; in these sulphate of ammonia gave percentage increases in yield of 18, 20 and 7.4. Evidence is produced that early dressings of sulphate of ammonia do not affect germination or plant establishment, but that they tend to increase tiller formation by the end of February.

Trace element uptake by two British Columbia forages as affected by poultry manure application

1991 ◽  
Vol 71 (3) ◽  
pp. 305-312 ◽  
Author(s):  
A. A. Bomke ◽  
L. E. Lowe
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Clay Soil ◽  
Poultry Manure ◽  
Yield Response ◽  
Silty Clay ◽  
Manure Application ◽  
Deep Pit ◽  
Loam Soil ◽  
Trace Element Uptake

Field experiments evaluated yield response to deep-pit poultry manure application to barley on a clay soil near Prince George and a grass-legume forage on a silty clay loam soil near Chilliwack, B.C. Substantial dry matter yield increases were measured at manure applications up to 20 t ha−1. Subsamples of both crops and the poultry manure were analyzed for Cu, Zn, Mn, Ba, Pb, Ni, Cr, Cd, B and Co. Selenium analyses were made on selected crop samples. There were no indications of toxicity problems even at 40 t ha−1, the highest application. Copper and Zn concentrations in forages were increased by the poultry manure and the Mn/Cu ratio tended to decrease with manure application. Key words: Orchardgrass, ladino clover, barley, micronutrients

scholarly journals Populasi Serangga Penyerbuk Kelapa Sawit Elaeidobius kamerunicus Faust dan Pengaruhnya terhadap Nilai Fruit Set pada Tanah Berliat, Berpasir dan Gambut di Kalimantan Tengah, Indonesia

Agrikultura ◽  
2017 ◽  
Vol 28 (1) ◽  
Author(s):  
Fizrul Indra Lubis ◽  
Sudarjat Sudarjat ◽  
Danar Dono
Keyword(s):  
Sandy Soil ◽  
Fruit Set ◽  
Clay Soil ◽  
Peat Soil ◽  
Soil Types ◽  
Palm Fruit ◽  
Central Kalimantan ◽  
Palm Weevil ◽  
Elaeidobius Kamerunicus ◽  
Set Value

ABSTRACTPopulation of soil palm weevil pollinator Elaeidobius kamerunicus FAUST and its impact on fruit setvalue at clay, sandy and peat soil types in central Kalimantan, di IndonesiaOil palm weevil pollinator Elaeidobius kamerunicus Faust plays an important role in the increasing oilpalm fruit set value. Along with the development of oil palm, fruit set problems occurred in recentdecades in some parts of Indonesia. An experiment was carried out on a seven years old oil palmplantation located at Selangkun Estate, Kotawaringin Barat, Central Kalimantan, Indonesia to find outthe influence of population E. kamerunicus on pollination efficiency at clay, sandy and peat soil types.Relative to other soil types, a high weevil population on male (50,811 weevils/ha ; 72 weevils/spikelet)and female (219 weevils) inflorescences had been recorded at clay soil. Fruit set value on clay soil 58.9%and significantly different with sandy soil of 49.8% and peat soil of 46.4%. Population E. kamerunicusper ha influenced fruit set value at clay, sandy and peat soil types. Number of E. kamerunicus visitedfemale inflorescences did not influenced fruit set value at clay, sandy and peat soil types.Keywords: Clay soil, Elaeidobius kamerunicus, fruit set, peat soil, population, sandy soil ABSTRAKSerangga penyerbuk kelapa sawit Elaeidobius kamerunicus FAUST berperan penting dalam peningkatannilai fruit set kelapa sawit. Seiring dengan perkembangan kelapa sawit, adanya permasalahan nilai fruitset telah terjadi dalam beberapa kurun waktu di beberapa wilayah Indonesia. Penelitian dilakukan diperkebunan kelapa sawit yang telah berumur tujuh tahun, berlokasi di Selangkung, Kotawaringin Barat,Kalimantan Tengah, Indonesia dan bertujuan untuk mengetahui pengaruh populasi E. Kamerunicusterhadap efisiensi penyerbukan pada tipe tanah liat, pasir dan gambut. Berdasarkan tipe tanahdilaporkan bahwa tingginya populasi kumbang pada bunga jantan yaitu (50.811 kumbang/ha; 72kumbang/spikelet) dan bunga betina yang sedang mekar (219 kumbang) pada tipe tanah berliat.Adapun, nilai fruit set pada tanah liat sebesar 58,9% dan berbeda nyata dibandingkan dengan tanahberpasir (49,8%) dan gambut (46,4%). Populasi E. kamerunicus per ha berpengaruh terhadap nilai fruitset pada tipe tanah liat, pasir dan gambut. Namun, jumlah E. kamerunicus yang mengunjungi bungabetina yang sedang mekar tidak berpengaruh terhadap nilai fruit set pada tipe tanah liat, pasir dangambut.Kata Kunci : Elaeidobius kamerunicus, Fruit set , Populasi, Tanah Gambut, Tanah liat, Tanah Pasir

Components of Error in Field Experiments with Cotton, Groundnuts, Kenaf and Sesame in the Central Sudan Rainlands. II . Variation in Plant Measurements Through the Season and a Discussion of Surface Drainage as a Source of Variation

1976 ◽  
Vol 12 (3) ◽  
pp. 225-240 ◽  
Author(s):  
H. R. B. Hack
Keyword(s):  
Field Experiments ◽  
Clay Soil ◽  
Branch Length ◽  
Dry Weight ◽  
Mean Square ◽  
Node Number ◽  
Surface Drainage ◽  
Central Sudan ◽  
Main Components ◽  
Uncontrolled Variation

Dry weight, stem and branch length and node number, and flower and fruit number where appropriate, were recorded through the season on cotton, groundnuts, kenaf and sesame in the central rainlands of the Sudan in 1965. For each sampling date variationwithin plotsandbetweenreplicate plots within blocksandtreatmentxblockinteraction have been studied, together with the effect of these components on the magnitude of the residual root mean square in the analysis oftreatmentsxblocks.The main components were usuallywithin plotandbetween replicate plots within blockerrors. Uncontrolled variation was unacceptably great, and was thought to be in large part the result of irregular surface drainage conditions. It seems more likely to be useful to include surface drainage contrasts in field experiments subject to high intensity rainfall on this impermeable clay soil than to attempt to increase precision alone.

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