Effect of temperature and moisture on kinetics of urea hydrolysis and nitrification

Soil Research ◽  
1987 ◽  
Vol 25 (2) ◽  
pp. 185 ◽  
Author(s):  
DS Yadav ◽  
V Kumar ◽  
M Singh ◽  
PS Relan
Keyword(s):  
Sandy Loam ◽  
Field Capacity ◽  
Urea Hydrolysis ◽  
Hydrolysis Rate ◽  
Effect Of Temperature ◽  
Activation Entropy ◽  
Clay Loam ◽  
Moisture Regimes ◽  
Loam Soil ◽  
Kinetics Of

The effects of temperature and moisture regimes on kinetics of urea hydrolysis in soils of Hisar (Typic Camborthids) and Hansi (Typic Ustochrepts) were studied. The rate constant (K) for first-order reaction increased with temperature from 10 to 35�C. Energy of activation (Ea), activation free energy (�F*) and activation entropy (�S*) between 10 and 35�C were 33.8, 81.8 kJ mol-1 and -176.55 K-1I in a sandy loam soil, and 29.2, 81 -6 kJ mol-I and - 155.3 J K-I in a clay loam soil, respectively. The hydrolysis rate was not a linear function of moisture content but increased with field capacity (F.C.). The rate of hydrolysis in both the soils followed the order: 20% F.C. < 40% F.C. < 80% F.C. = 100% F.C. The rate for flooded soil was between those for 20% and 40% F.C. for sandy loam, and between 40 and 80% F.C. for the clay loam. The added urea was completely hydrolysed in 3 days at all moisture regimes except 20% F.C.; maximum NH4+-N was found at the third day, then decreased thereafter. The time at which NO2- first appeared varied with treatments, but then it persisted throughout the 24-day incubation in all treatments.

scholarly journals Adsorption-Desorption of Hexaconazole in Soils with Respect to Soil Properties, Temperature, and pH

2016 ◽  
Vol 4 (6) ◽  
pp. 493 ◽  
Author(s):  
Maznah Zainol ◽  
Halimah Muhamad ◽  
Ismail Bin Sahid ◽  
Idris Abu Seman
Keyword(s):  
Sandy Loam ◽  
Equilibrium Phase ◽  
Organic Matter Content ◽  
Organic Content ◽  
Soil Types ◽  
Effect Of Temperature ◽  
Clay Loam ◽  
Kd Values ◽  
Loam Soil ◽  
Adsorption Desorption

The effect of temperature and pH on adsorption-desorption of fungicide hexaconazole was studied in two Malaysian soil types; namely clay loam and sandy loam. The adsorption-desorption experiment was conducted using the batch equilibration technique and the residues of hexaconazole were analysed using the GC-ECD. The results showed that the adsorption-desorption isotherms of hexaconazole can be described with Freundlich equation. The Freundlich sorption coefficient (Kd) values were positively correlated to the clay and organic matter content in the soils. Hexaconazole attained the equilibrium phase within 24 h in both soil types studied. The adsorption coefficient (Kd) values obtained for clay loam soil and sandy loam soil were 2.54 mL/g and 2.27 mL/g, respectively, indicating that hexaconazole was weakly sorbed onto the soils due to the low organic content of the soils. Regarding thermodynamic parameters, the Gibb’s free energy change (ΔG) analysis showed that hexaconazole adsorption onto soil was spontaneous and exothermic, plus it exhibited positive hysteresis. A strong correlation was observed between the adsorption of hexaconazole and pH of the soil solution. However, temperature was found to have no effect on the adsorption of hexaconazole onto the soils; for the range tested.

TOLERANCE OF EARLY-MATURING SOYBEAN CULTIVARS TO METRIBUZIN

1986 ◽  
Vol 66 (1) ◽  
pp. 125-130 ◽  
Author(s):  
G. H. FRIESEN ◽  
D. A. WALL
Keyword(s):  
Sandy Loam ◽  
Controlled Environment ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Soybean Cultivars ◽  
Early Maturing ◽  
Glycine Max L ◽  
Loam Soil ◽  
Environment Chamber ◽  
Chamber Studies

McCall, Maple Presto, Maple Amber and OT80-3 soybean (Glycine max (L.) Merr.) cultivars were evaluated under field conditions for their response to metribuzin. Maple Amber was found to be less tolerant than the other cultivars. In controlled environment chamber studies, injury to this cultivar was more severe on a sandy loam soil than on a clay loam soil. Fall applications of metribuzin, alone or tank-mixed with trifluralin, were tolerant to Maple Amber soybeans and such applications may offer a practical alternative to spring treatments for broad spectrum weed control in the less tolerant soybean cultivars grown in Manitoba.Key words: Metribuzin, trifluralin, preplant incorporation, fall treatments, soybean cultivars

scholarly journals Biochar Improves Plant Growth and Reduces Nutrient Leaching in Red Clay Loam and Sandy Loam

2012 ◽  
pp. 86-90 ◽  
Author(s):  
Kalpana Pudasaini ◽  
Nanjappa Ashwath ◽  
Kerry Walsh ◽  
Thakur Bhattarai
Keyword(s):  
Sandy Loam ◽  
Vegetable Production ◽  
Clay Loam ◽  
Plant Establishment ◽  
Clay Loam Soil ◽  
Red Clay ◽  
Green Waste ◽  
Loam Soil ◽  
Shoot Weight ◽  
Water Holding

A factorial pot experiment was conducted using two types of soils (sandy loam and red clay loam) that are commonly used for commercial vegetable production in Bundaberg, region of Central Queensl and Australia. The soils were amended with 0, 25, 50 and 75 t/ha of green waste biochar and minimum doses of N, P and K (30 kg/ha, 30 kg/ha and 40 kg/ha respectively). After two weeks of plant establishment, the pots were leached with 1.5 litres of deionised water at week intervals, and cation concentrations of the leachate were determined. In 25 t/ha biochar treatment, there was a significant (P<0.05) reduction in K and Ca leaching by 40% and 26% respectively from sandy loam, and of Ca by 23% from the red clay loam. Soil water holding capacity and soil organic carbon were also increased in both biochar treated soils. After 12 weeks of growth, shoot weight was signifi cantly (P<0.05) higher in 25 t/ha biochar-treated sandy loam and red clay loam (32% and 31% respectively). These results clearly demonstrated that a higher yield of capsicum can be achieved from green waste biochar application in sandy loam and red clay loam at 25 t/ha biochar.DOI: http://dx.doi.org/10.3126/hn.v11i1.7221 Hydro Nepal Special Issue: Conference Proceedings 2012 pp.86-90

scholarly journals LEAF GAS EXCHANGE CHARACTERISTICS OF FOUR PAPAYA GENOTYPES DURING DIFFERENT STAGES OF DEVELOPMENT

2001 ◽  
Vol 23 (3) ◽  
pp. 522-525 ◽  
Author(s):  
ELIEMAR CAMPOSTRINI ◽  
OSVALDO KIYOSHI YAMANISHI ◽  
CARLOS A. MARTINEZ
Keyword(s):  
Gas Exchange ◽  
Carica Papaya ◽  
Leaf Gas Exchange ◽  
Carbon Dioxide Concentration ◽  
Field Capacity ◽  
Experimental Period ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Loam Soil ◽  
Gas Exchange Characteristics

In this research, was used four papaya (Carica papaya L.) genotypes: three from the 'Solo ( Sunrise Solo TJ, Sunrise Solo 72/12 and Baixinho de Santa Amália) group and one from the 'Formosa' group (Know-You 01). They were grown in plastic pots containing a sandy-clay-loam soil subjected to pH correction and fertilization, under greenhouse conditions. Throughout the experimental period plants were subjected to periodic irrigation to maintain the soil humitidy around field capacity. The experiment was conducted 73 days after sowing. In all genotypes, leaf gas exchange characteristics were determined. The net photosynthetic rate (A, mumol m-2 s-1 ), stomatal conductance (g s mol m-2 s-1), leaf temperature (T I, 0C) and intercellular carbon dioxide concentration (ci, muL L-1) on the 4th, 5th, 6th, 7th, 8th and 9th leaves from the plant apex were determined. No significant differences were observed for A, g s, c i, or Tl either among the leaves sampled from any of the genotypes. A was positively correlated with g s and in the other hand T I and g s were negatively correlated. The results suggest that, for 73 DAP, all the sampled papaya leaves functioned as sources of organs.

scholarly journals Design, Construct and Evaluation of a Single Row Hand-Pushed Mechanical Weed Control Machine

2021 ◽  
Vol 25 (3) ◽  
pp. 401-406
Author(s):  
A. Saleh ◽  
M.L. Suleiman
Keyword(s):  
Weed Control ◽  
Sandy Loam ◽  
Labour Force ◽  
Field Capacity ◽  
Vegetable Production ◽  
Loam Soil ◽  
Human Effort ◽  
Field Efficiency ◽  
Peasant Farmers ◽  
Control Machine

Weed control is one of the major problems in crop and vegetable production in Nigeria. Most of the peasant farmers use manual weeders in their cultivation, a process that is costly, labour intensive and time consuming. The process does not also give the farmer adequate returns to enable him breakeven. It is, therefore, necessary to design a weeding equipment which minimize the human effort and provide efficient work output for the peasant farmer. This study focus on designing, construction and evaluation of a hand-pushed weed control machine that would eliminate the challenges being faced by the farmer in weeding. Materials selected to suit the construction of the weeder are durable and locally available, easily replaced if damaged and at affordable cost. They include mild steel (3mm, 5mm), 30 mm circular (hollow) pipes, 10 mm diameter steel rod, and 40 cm pneumatic tyre. The developed weeding machine was evaluated in the experimental farm of IAR with impressive results. It works well in sandy loam soil of about 25.65% moisture content and requires less labour force compared to the manual hoe. It has about 84.7% weeding efficiency, 0.0129ha/hr effectivefield capacity, 0.019ha/hr theoretical field capacity and 68% field efficiency. The average cost of the weeding is N21, 000:00. Keywords: Manual weeding, hand-pushed weeder, weeding efficiency, field efficiency

Leaching and mobility of carbofuran from granular and alginate controlled release formulations

2000 ◽  
Vol 134 (4) ◽  
pp. 405-412 ◽  
Author(s):  
A. S. MAREI ◽  
H. R. SOLTAN ◽  
A. MOUSA ◽  
A. KHAMIS
Keyword(s):  
Controlled Release ◽  
Sandy Loam ◽  
Soil Column ◽  
Sandy Loam Soil ◽  
Flooded Soil ◽  
Clay Loam ◽  
Sandy Clay Loam ◽  
Sandy Clay ◽  
Controlled Release Formulations ◽  
Loam Soil

Controlled release (CR) formulations can significantly influence the fate of carbofuran in the environment. The influence of three alginate-encapsulated CR formulations compared with the granular formulation (G10%) on the mobility of carbofuran in sandy clay loam soil and sandy loam soil was investigated. In flooded soil the leaching potential of the three alginate controlled release formulations tested was decreased more than nine times (not more than 3%) compared with the G10% (28%). Most of the released carbofuran was confined to the top 0–5 cm of the soil column followed by the second 5–10 cm layer and the least was found in the fourth section (15–20 cm). The data obtained for a sandy loam soil irrigated by drip irrigation showed that the greatest proportion of carbofuran leached through the columns was from the G10% (52%) compared with 3–4% from CR formulations over a 30-day period. The carbofuran concentrations found in different soil depths showed similar trends to those for the flooded soil. Based on the residue levels recorded within the 20 cm depth, the relative retention ratio of carbofuran in sandy clay loam versus sandy loam soil was 1·2[ratio ]1 for the controlled release formulations and 1·9[ratio ]1 for the G10%.

scholarly journals Effect of growing media on mat type seedling raised for mechanical rice transplanting 

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 157-167
Author(s):  
Hossen Anwar M ◽  
Hossain Mosharraf M ◽  
Haque Enamul M ◽  
Bell Richard W
Keyword(s):  
Rice Straw ◽  
Rice Bran ◽  
Sandy Loam ◽  
Organic Fertilizer ◽  
Poultry Litter ◽  
Cow Dung ◽  
Clay Loam ◽  
Clay Loam Soil ◽  
Loam Soil ◽  
Rolling Quality

Mechanical transplanted seedling must meet the requirements of standard seedling block with uniform distribution of seedlings and inter-twisting roots for rolling. This study was conducted to identify the effect of growing media on mat type seedling raised for mechanical transplanting at Bangladesh Rice Research Institute (BRRI), Gazipur during the period of 2012–2014 covering two dry and cold seasons (Boro) and one wet season (Aman). Seedling were raised on plastic tray using sandy loam and clay loam soil mixed with decomposed cow-dung, mustard cake, rice straw organic fertilizer, rice bran, poultry litter and vermicompost at the rate of 0.0, 10, 20, 30 and 40%. Rolling quality of the seedling mat decreased and seedling height increased with the increased of mixing rate of organic fertilizer except rice bran and mustard cake. Averaged across three seasons, 10 to 30% cow-dung, rice straw organic fertilizer, vermicompost, 10% poultry litter and 20 to 30% rice bran with both types of soil was found suitable for seedling mat and seedling height. However, seedling varied among the organic fertilizers with both types of soil in the order of cow-dung &gt; rice bran &gt; vermicompost &gt; poultry liter &gt; rice straw organic fertilizer &gt; mustard cake. Clay loam soil showed better performance on rolling quality over sandy loam soil.

Acetylene reduction by non-symbiotic bacteria in artificial soil aggregates amended with glucose

1974 ◽  
Vol 20 (6) ◽  
pp. 877-881 ◽  
Author(s):  
C. I. Mayfield ◽  
R. L. Aldworth
Keyword(s):  
Sandy Loam ◽  
Soil Aggregates ◽  
Peripheral Zone ◽  
Sandy Loam Soil ◽  
Artificial Soil ◽  
Clay Loam ◽  
Sandy Clay Loam ◽  
Sandy Clay ◽  
Loam Soil ◽  
Soil Activity

The C2H2-reduction assay was used to study the activity of non-symbiotic N2-fixing bacteria in glucose-amended artificial soil aggregates prepared from a sandy clay loam and a sandy loam soil. Anaerobic incubation under nitrogen resulted in significantly higher rates and greater total quantities of C2H2 reduction than did incubation in air. In the sandy clay loam soil activity under both incubation conditions was due to anaerobic N2-fixing bacteria, whereas in the sandy loam soil aerobic N2-fixing bacteria also proliferated in the aggregates. Direct observation of sectioned aggregates by fluorescence microscopy showed that peripheral zone 1 mm thick sup ported the growth of aerobic microorganisms. The anaerobic microsites in the interior of the aggregates were well protected since disruption procedures involving vigorous shaking with aerated water were required to allow O2 to penetrate and inhibit the anaerobic activity.

Effect of Commonly used Turfgrass Herbicides on Bermudagrass (Cynodon dactylon) Root Growth

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 641-647 ◽  
Author(s):  
Frederick M. Fishel ◽  
G. Euel Coats
Keyword(s):  
Root Growth ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Root Weight ◽  
Clay Loam ◽  
Soil Layers ◽  
Sandy Clay Loam ◽  
Fine Sandy Loam ◽  
Sandy Clay ◽  
Loam Soil

Experiments were conducted in 1990 and 1991 to determine bioavailability of PRE herbicides at three soil profile depths and two soil types in established common bermudagrass sods. Prodiamine and oryzalin reduced ‘Tifgreen’ bermudagrass root growth in the 5- to 7.5-cm layer of a Bosket very fine sandy loam soil at 2 and 4 wk after treatment in 1991. These herbicides decreased bermudagrass root weight in both the Bosket and Marietta sandy clay loam both years in samples taken from the 2.5- to 5-cm depth layer. In the 0- to 2.5-cm soil layer, all herbicides reduced root weight in 1990. In a bioassay, prodiamine caused decreased Tifgreen bermudagrass root growth at concentrations as low as 4 ppb by wt in the very fine sandy loam soil, while 8 ppb was necessary in the sandy clay loam soil. Prodiamine was detected in the very fine sandy loam at 4 wk after treatment at all depths in 1991 (65, 45, and 39 ppb in the 0- to 2.5-, 2.5- to 5-, and 5- to 7.5-cm soil layers, respectively). Oryzalin was also detected at all depths in 1991 when sampled at 2 and 4 wk after treatment in the very fine sandy loam. Pendimethalin was present in concentrations of 38, 39, and 37 ppb in the sandy clay loam at 2 wk after treatment in the 0- to 2.5-, 2.5- to 5-, and the 5- to 7.5-cm soil layers, respectively. Pendimethalin was also detected in the very fine sandy loam at 2 wk after treatment at concentrations of 55, 69, and 36 ppb in the 0- to 2.5-, 2.5- to 5-, and 5- to 7.5-cm soil layers, respectively.

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