Osmotic and ionic effects of various electrolytes on the growth of wheat

Soil Research ◽  
2010 ◽  
Vol 48 (2) ◽  
pp. 120 ◽  
Author(s):  
Pichu Rengasamy
Keyword(s):  
Soil Solution ◽  
Sandy Loam ◽  
Field Capacity ◽  
Threshold Value ◽  
Electrolyte Solutions ◽  
Osmotic Effect ◽  
Matter Production ◽  
Loam Soil ◽  
Hoagland Nutrient Solution ◽  
Ionic Effects

Pot experiments were conducted using a sandy loam soil and various electrolyte solutions such as NaCl, CaCl2, Na2SO4, and Hoagland nutrient solution containing all macro- and micro-nutrient elements in appropriate proportions, inducing different electrical conductivity (EC) levels of the soil solution during the growth of Krichauff wheat while the water content in the pot soils was maintained at field capacity. The resulting differences in dry matter production after 40 days of growth clearly indicated the continuous operation of osmotic effect as the EC of the soil solution increased from 0.7 to 41.0 dS/m. However, the osmotic effect became dominant and severely restricted plant growth when the soil solution EC increased above a ‘threshold value’, which was 25 dS/m, corresponding to an osmotic pressure of 900 kPa, in this experiment. Below this EC value, particularly at low EC values, ionic effects due to Na+, Ca2+, SO42–, and Cl– were also evident, but it could not be concluded whether these effects were due to toxicity or ion imbalance. The osmotic effect at EC values above the threshold resulted in greatly reduced water uptake from pot soils, the unused water being in the range 89–96% of the field capacity of the soil. Water use efficiency is a major factor in profitable and sustainable dryland agriculture. Both soil management and selection and breeding of salt-tolerant plants should concentrate on ensuring that the threshold EC value for severe osmotic effects is not reached under field conditions.

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

EFFECTS OF IRRIGATION AND NITROGEN ON A NATURAL PASTURE SWARD

1978 ◽  
Vol 58 (2) ◽  
pp. 347-356
Author(s):  
W. N. BLACK
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Field Capacity ◽  
Early Spring ◽  
Naturally Occurring ◽  
Natural Pasture ◽  
Loam Soil ◽  
Grazing Period

Irrigation and nitrogen (N) requirements of a natural pasture sward were studied on a Charlottetown sandy loam soil over a 5-yr period. The soil moisture content at the 0-to 15- and 15- to 30-cm depths was determined at from 7- to 10-day intervals, while irrometer soil moisture readings at 15-, 30-, and 45-cm depths were recorded more frequently during the grazing seasons. Soil moisture content in irrigated plots averaged 92 and 94% of field capacity, respectively, at 0- to 15- and 15- to 30-cm sampling depths. In non-irrigated plots, corresponding values were 77 and 82%. N treatments resulted in significant dry matter (DM) increases over untreated plots. Yield differences among plots receiving 56, 84, and 112 kg of N/ha in mid-June and again in mid-August were not significant. Early spring and September applications of N at 56 kg/ha, combined with mid-June and early August supplements of N at 84 kg/ha were superior to all other treatments in prolonging the grazing period. Neither irrigation nor N affected the characteristic yield decline of naturally occurring forage species in mid- and late-season. Mean DM production for the 5-yr period, and for years, showed no significant N treatment × moisture level interaction. While irrigation failed to increase yields significantly, livestock preferred to graze the irrigated plots. As a result of less competition from grasses, volunteer white clover became better established, and constituted a larger percentage of the sward than on non-irrigated plots.

Responses of Rhodes Grass and Overseeded Legumes to Nitrogen and Potash Fertilizers and to the Availability of Soil Potassium in Israel

1966 ◽  
Vol 2 (4) ◽  
pp. 255-263 ◽  
Author(s):  
A. Dovrat
Keyword(s):  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Sandy Loam ◽  
Normal Growth ◽  
Rhodes Grass ◽  
Matter Production ◽  
Potassium Starvation ◽  
Loam Soil ◽  
Chloris Gayana ◽  
Equal Split

SummaryResults are reported from experiments with nitrogen and potash fertilizers in irrigated Rhodes grass (Chloris gayana), into which annual winter legumes, e.g. berseem (Trifolium alexandrinum) and vetch (Vicia sativa) were overseeded. The experiments were carried out over a three year period on a sandy loam soil at Bet Dagan Experimental Farm, Israel. Ammonium sulphate, applied in equal split rates of up to 384 lb N per acre, linearly increased dry matter yields of Rhodes grass, and the increase of yield proportionally increased the uptake of K by harvest. The K content of the dry matter decreased with increasing nitrogen fertilization to 0·47 per cent which, however, was still found sufficient for maintaining maximum production of Rhodes grass. The yield of annual winter legumes decreased proportionally to the amount of nitrogen fertilizer applied during the summer. Acute potassium starvation was observed. An autumn application of potassium chloride restored dry matter production to normal levels. Availability of soil K, expressed in terms of energies of replacement [ΔF(− 1)], decreased proportionally to the amount of nitrogen fertilizer applied. When ΔF reached approximately 4,250 cal/mol, overseeded legumes were K-deficient, whereas Rhodes grass at that value was still able to extinct sufficient K from the soil for normal growth.

scholarly journals Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

2016 ◽  
Vol 14 (2) ◽  
pp. e1103 ◽  
Author(s):  
Leila Esmaeelnejad ◽  
Mehdi Shorafa ◽  
Manouchehr Gorji ◽  
Seiyed M. Hosseini
Keyword(s):  
Soil Properties ◽  
Sandy Loam ◽  
Field Capacity ◽  
Particle Sizes ◽  
Water Drainage ◽  
Mean Weight Diameter ◽  
Binding Agents ◽  
Loam Soil ◽  
Plant Available Water ◽  
Air Capacity

In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C) from two feedstocks (rice husk and apple wood chips). Produced biochars were prepared at two diameters (1-2 mm and <1 mm) and mixed with soil at a rate of 2% (w/w). Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks) was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks.

EFFECT OF SOIL MOISTURE CONTENT AND STAGE OF DEVELOPMENT ON COLD-HARDINESS OF THE ALFALFA PLANT

1965 ◽  
Vol 45 (3) ◽  
pp. 211-218 ◽  
Author(s):  
F. W. Calder ◽  
L. B. MacLeod ◽  
L. P. Jackson
Keyword(s):  
Cold Hardiness ◽  
Root Exudate ◽  
Soil Moisture Content ◽  
Developmental Stages ◽  
Environmental Control ◽  
Sandy Loam ◽  
Field Capacity ◽  
Freezing Damage ◽  
Stage Of Development ◽  
Loam Soil

Alfalfa plants were grown in the greenhouse to three developmental stages, (1) vegetative (48 days old), (2) early bud (62 days old), and (3) 50% bloom (78 days old), hardened and subjected to freezing temperatures in an environmental control chamber. Prior to hardening, the Tormentine sandy loam soil in which the plants were growing was brought to three moisture levels, (1) 25% of field capacity, (2) field capacity, (3) and saturation.Electrical conductivity of plant exudate from top growth of plants decreased during hardening and with freezing. Conductivity of root exudate increased during hardening but decreased during freezing.Plants were rated for freezing damage, immediately after freezing and 10 days later. Recovery was significantly higher for plants grown on soils at held capacity than at saturation. Differences in regrowth between 25% of field capacity and field capacity were not significant. Total available carbohydrate content and etiolated regrowth were also higher for plants grown in soil at field capacity.Saturated soil had an extremely adverse effect on development of cold-hardiness of alfalfa plants as compared with effect of field capacity and 25% of held capacity.Plants that were mature before hardening and freezing were more hardy under field capacity conditions than less mature stages of plants, as shown by weight of aerial and root portions of plants, carbohydrates, conductivity, growth without light, and rating of recovery after freezing.

scholarly journals An Improved Leaf Disc Bioassay for Detecting Calonectria pseudonaviculata in Soil and Potting Media

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1626-1631 ◽  
Author(s):  
Norm Dart ◽  
Chuanxue Hong ◽  
William Tyler Bradley
Keyword(s):  
Sandy Loam ◽  
Leaf Disc ◽  
Field Capacity ◽  
The United States ◽  
Sandy Loam Soil ◽  
The United Kingdom ◽  
Potting Media ◽  
Loam Soil ◽  
Optimal Incubation

Boxwood blight caused by Calonectria pseudonaviculata results in severe defoliation and dieback to boxwood (Buxus spp.). The pathogen was first described in the United Kingdom and New Zealand in the mid to late 1990s and has since spread throughout Europe and most recently to the United States and Canada. While many Calonectria spp. have an epidemiologically significant soil phase, little is known of the role of the soil phase of C. pseudonaviculata in the epidemiology of boxwood blight. We optimized a leaf disc bioassay for detecting and quantifying this pathogen in soil and compared this bioassay with a standard soil plating assay originally developed for quantifying Calonectria using a Suffolk sandy-loam soil. Additionally, the sensitivity of both assays was compared among three distinct soil types (sand-loam, silt-loam, and sand-peat potting media). The optimal incubation time for baiting C. pseudonaviculata from soil using the leaf disc bioassay was 96 h. The optimal soil moisture for the bioassay was 1,000% of field capacity (flooded with 3 to 5 mm water). The leaf disc bioassay was able to detect C. pseudonaviculata at levels as low as 1 microsclerotium/ g soil while the soil plating bioassay was unable to detect the pathogen below inoculum levels of 10 microsclerotia/g soil in the Suffolk sandy-loam soil. Soil type had a significant impact on the sensitivity of both assays.

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 Water productivity for sugar and biomass of sugarcane varieties

2017 ◽  
Vol 21 (9) ◽  
pp. 618-622 ◽  
Author(s):  
Daniel P. V. Leal ◽  
Rubens D. Coelho ◽  
Fernando da S. Barbosa ◽  
Eusimio F. Fraga Júnior ◽  
Robson Mauri ◽  
...  
Keyword(s):  
Clay Soil ◽  
Sandy Loam ◽  
Near Field ◽  
Water Productivity ◽  
Field Capacity ◽  
Ratoon Crop ◽  
Fresh Biomass ◽  
Sugarcane Varieties ◽  
Loam Soil ◽  
Depth Water

ABSTRACT The aim of this study was to evaluate the water productivity into biomass and into sugar for 23 sugarcane varieties (second ratoon crop) under two levels of drip irrigation. Two experiments were conducted in a greenhouse. Experiment 1 comprised nine sugarcane varieties grown in a clay soil and Experiment 2 was composed of 14 varieties in a sandy-loam soil. Moreover, two irrigation treatments were adopted: T100 - full irrigation with 100% crop evapotranspiration replacement, maintaining soil moisture near field capacity for each variety; and T70 - irrigation with 70% T100 water depth. Water productivity was evaluated in terms of stem fresh biomass (WPFB) and sugar (WPGSY). The results showed that WPFB ranged from 11.45 to 18.45 kg m-3. The highest values were observed for varieties CTC14, CTC6, RB867515, and SP81-3250 (in T100) and for the varieties CTC6 and CTC14 (in T70). The WPGSY values ranged from 1.68 to 2.22 kg m-3, with emphasis placed on CTC6, RB9675-15, SP81-3250, and RB925211 (in T100) and on CTC6, CTC14, and SP81-3250 (in T70).

scholarly journals Depth distribution of preferential flow patterns in a sandy loam soil as affected by tillage

1997 ◽  
Vol 1 (4) ◽  
pp. 769-776 ◽  
Author(s):  
C. T. Petersen ◽  
S. Hansen ◽  
H. E. Jensen
Keyword(s):  
Cross Sections ◽  
Preferential Flow ◽  
Sandy Loam ◽  
Field Capacity ◽  
Flow Patterns ◽  
Structural Features ◽  
Sandy Loam Soil ◽  
Soil Conditions ◽  
Loam Soil ◽  
Flow Pathways

Abstract. Dye-tracer studies using the anionic dye Brilliant Blue FCF were conducted on a structured sandy loam soil (Typic Agrudalf). 25 mm of dye solution was applied to the surface of 11 1.6 x 1.6 m field plots, some of which had been subjected to conventional seed bed preparation (harrowing) while others had been rotovated to either 5 or 15 cm depth before sowing. The soil was excavated to about 160 cm depth one or two days after dye application. Flow patterns and structural features appearing on vertical or horizontal cross sections were examined and photographed. The flow patterns were digitized, and depth functions for the number of activated flow pathways and the degree of dye coverage were calculated. Dye was found below 100 cm depth on 26 out of 33 vertical cross sections made in conventionally tilled plots showing that preferential flow was a prevailing phenomenon. The depth-averaged number of stained flow pathways in the 25-100 cm layer was significantly smaller in a plot rotovated to 5 cm depth than in a conventionally tilled plot, both under relatively dry initial soil conditions and when the entire soil profiles were initially at field capacity. There were no examples of dye penetration below 25 cm depth one month after deep rotovation. Distinct horizontal structures in flow patterns appearing at 20-40 cm depth coupled with changes in flow domains indicated soil layering with abrupt changes in soil structure and hydraulic properties.

scholarly journals Nitrate and potassium movement in a sandy loam soil cultivated with fertigated grapevine (Vitis vinifera /L.) in the Brazilian semiarid

2018 ◽  
Vol 40 (5) ◽  
Author(s):  
Alexsandro Oliveira da Silva ◽  
Luis Henrique Bassoi ◽  
Davi José Silva
Keyword(s):  
Soil Solution ◽  
Nitrogen Fertilization ◽  
Sandy Loam ◽  
Water Flux ◽  
Fertilizer Application ◽  
Sandy Loam Soil ◽  
Vitis Vinifera L ◽  
Growing Seasons ◽  
Brazilian Semiarid ◽  
Loam Soil

Abstract Fertigation can increase the efficiency of fertilizer application and facilitate the nutritional management of a crop. Thus, nitrate and potassium movements in a sandy loam soil were evaluated as function of fertilizer doses during three growing seasons of the grapevine cv. Syrah grafted on Paulsen 1103 rootstock (June to October 2013, February to June 2014, and August to November 2014) in Petrolina, state of Pernambuco, Brazil. Five doses of N (0, 15, 30, 60 and 120 kg ha-1) and five doses of K2O (0, 15, 30, 60 and 120 kg ha-1) were combined in a fractional 52 factorial design, totaling 13 combinations, in a randomized blocks experiment with four replications. The concentrations of nitrate and potassium in the soil solution were determined. Samples were collected by porous cup extractors installed at 0.4 and 0.6 m depths. The movement of these ions was obtained by the product between their concentration in the soil solution and the soil water flux density. The increase in nitrogen fertilization promoted a greater movement of NO3- (62.2 kg ha-1) in the soil. The movement of K+ was also observed in two growing seasons .

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