Properties Of Calcareous Soil Research Articles

AMELIORATING CALCAREOUS SOIL PROPERTIES AND AGRICULTURE METHODS FOR ACHIEVING THE SUSTAINABLE AGRICULTURE ASPECT

The main objective of this investigation was to ameliorate calcareous soil properties, i.e., some hydrophysical and chemical properties of the sandy loam soil by using organic manure, i.e., composted rice straw at rate of 7.87 Mg f-1 +50%NPK and chicken manure at rate of 4.08 Mg f-1 +50%NPK as well as applying some agriculture methods, i.e., lines and prose for achieving the sustainable agriculture aspect. The field experiments were conducted in private farm of El Nubaria area, El-Behera Governorate, Egypt. Yield of wheat crop as well as the concentrations of micronutrient in straw and grains was determined. Application of either composted rice straw or chicken manure significantly improved the hydrophysical properties of the tested soil, i.e., bulk density, total porosity, pore size distribution, soil water retention and hydraulic conductivity. Composted rice straw has a preference to improve the hydrophysical properties compared to chicken manure. In addition, methods of agriculture treatments had no significant effect on soil hydrophysical properties.Concerning the effect of organic fertilizers application along with applying lines agriculture on pH, ECe, OM and CaCO3 content and chemically available Fe, Mn, zn and Cu in the cultivated soil, chicken manure was better than composted rice straw. Grain and straw yields of wheat plants as well as concentrations of Fe, Mn, zn and Cu in straw or in grains of wheat were significantly increased due to organic fertilizers application and use of lines agriculture methods. Lines agricultural method gave 5.70 % greater grain yield and 3.54 % straw yield over the prose agricultural method. Lines methods emphasized the role of applied organic manure on improving soil properties and consequently, increasing the availability of Fe, Mn, Zn and Cu in the calcareous soil. Where, lines agriculture method was the best treatments compared to prose method, which reduces the growth of roots and plant. In general, the study recommends using the chicken manure (4.08 Mg f-1+50% NPK recommended rate) or composted rice straw (7.87 Mg f-1+ 50% NPK recommended rate) with lines agriculture methods, which will give better results in increasing the productivity of calcareous soils. Thus, these treatments can replace entirely or partially N, P and K mineral fertilizers, which reduce production costs and conserve the environment from chemical pollution hazards on human and animal health.

Dynamics of Organic C Mineralization and the Mobile Fraction of Heavy Metals in a Calcareous Soil Incubated with Organic Wastes

Organic wastes such as sewage sludge and compost increase the input of carbon and nutrients to the soil. However, sewage sludge-applied heavy metals, and organic pollutants adversely affect soil biochemical properties. Therefore, an incubation experiment lasting 90 days was carried out to evaluate the effect of the addition of two sources of organic C: sewage sludge or composted turf and plant residues to a calcareous soil at three rates (15, 45, and 90 t of dry matter ha−1) on pH, EC, dissolved organic C, humic substances C, organic matter mineralization, microbial biomass C, and metabolic quotient. The mobile fraction of heavy metals (Zn, Cd, Cu, Ni, and Pb) extracted by NH4NO3 was also investigated.The addition of sewage sludge decreased soil pH and increased soil salinity to a greater extent than the addition of compost. Both sewage sludge and compost increased significantly the values of the cumulative C mineralized, dissolved organic C, humic and fulvic acid C, microbial biomass C, and metabolic quotient (qCO2), especially with increasing application rate. Compared to compost, the addition of sewage sludge caused higher increases in the values of these parameters. The values of dissolved organic C, fulvic acid C, microbial biomass C, metabolic quotient, and C/N ratio tended to decrease with time. The soil treated with sewage sludge showed a significant increase in the mobile fractions of Zn, Cd, Cu, and Ni and a significant decrease in the mobile fraction of Pb compared to control. The high application rate of compost resulted in the lowest mobility of Cu, Ni, and Pb. The results suggest that biochemical properties of calcareous soil can be enhanced by both organic wastes. But, the high salinity and extractability of heavy metals, due to the addition of sewage sludge, may limit the application of sewage sludge.

Breeding soybean for resistance to iron-deficiency chlorosis and soybean cyst nematode

Iron-deficiency chlorosis (IDC) and soybean cyst nematode (SCN) result in yield and income losses for soybean growers in the U.S. Breeding programs are identifying soybean genotypes with resistance to IDC using calcareous soils infested with SCN, where SCN might interfere with evaluation. Our first objective was to examine whether associations could be established for chlorosis symptoms with SCN infestation of soybean grown on SCN-infested calcareous soils. Two breeding populations, their parents, and five SCN-susceptible, IDC-control genotypes (IDC controls) were evaluated for IDC symptoms on SCN-infested calcareous soils in 2000 and 2001. In general, no significant correlations were detected between chlorosis expression and SCN infestation in either year, although a negative correlation (r = −0.93, p ≤ 0.05) was observed for the IDC controls in 2001. For our second objective, we examined the relationship between genotype resistance to SCN and IDC. Although IDC controls were all equally susceptible to SCN and chlorosis observed in the field and nutrient solution was similar, SCN-resistant genotypes expressed resistance to IDC in the field, but severe susceptibility to IDC in nutrient solution. Our third objective was to investigate the value of calcareous soil properties to predict IDC in soybean grown on SCN-infested calcareous soils. For one breeding population in 2001, positive correlations (p ≤ 0.05) were detected for chlorosis with calcium carbonate (r = 0.62) and electrical conductivity (r = 0.59), and a negative correlation (r = –0.41) with soil Fe-DTPA-TEA. No significant correlations were observed for the remaining genotypes. Our study indicated that associations between IDC, SCN, and calcareous soil properties are dependent on genotype and environment. In addition, our study demonstrated a potential association between plant health and SCN reproduction in SCN-susceptible genotypes, the possibility that SCNresistant genotypes may be sensitive to iron availability, and the importance of genotype on the detection of associations between IDC expression and SCN infestation.

Phosphorus Transformations and Their Relationships with Calcareous Soil Properties of Southern Western Australia

The agronomic effectiveness of phosphate fertilizers is strongly affected by reactions of P with soil constituents. The transformation of P added to soil and the effect of soil properties on these transformations was investigated for 14 alkaline and calcareous soils from southern Western Australia. The decline of NaHCO3‐extractable P (Olsen‐P) with time followed a second order kinetic equation. The kinetic rate constant (k) increased with increasing oxalate‐extractable Fe (Feo), citrate–dithionite–bicarbonate (CDB)‐extractable Al and Fe (Ald and Fed), CaCO3‐free clay content, cation‐exchange capacity (CEC), and ratio of CDB‐extractable Fe (Fed) to active CaCO3 equivalent (ACCE), and k decreased with increasing ACCE. A combination of these soil properties described 93% of the variation in rate constant, of which 78% of the variation was predicted by the Fed/ACCE ratio alone. A combination of clay related properties (Ald, clay, Feo, and CEC) described 62% of the variation in Ca2–P determined by specific extraction. Carbonate‐related properties (ACCE and CCE) together described 71% variation in Ca8–P. Clay‐related and carbonate‐related properties jointly described 97% and 81% of the variation in Fe–P and Olsen‐P respectively. Surface area (SA) and Ald together accounted for 43% of the variation in Al–P. Scanning electron microscopy analyses showed that added P was uniformly distributed in the soil matrix to the limit of the spatial resolution of the technique (≈2 μm).

Manganese retention by selected calcareous soils as related to soil properties1

Calcareous soils often need supplemental manganese (Mn) to support optimum plant growth, but some reports show that the apparent recovery of applied Mn is very low in such soils, i.e., nearly all of the applied Mn is retained in the soil. This experiment was conducted to find the relationship between the retained Mn and selected properties of calcareous soils. Eleven surface (0–20 cm) soil samples with pH ranging from 7.7 to 8.1 and calcium carbonate equivalent (CCE) ranging from 20 to 50% were used in the Mn adsorption study. Two‐gram subsamples of each soil were equilibrated with 20 mL of 0.01M CaCl2 solutions initially containing 10 to 200 mg Mn L‐1. The Mn that disappeared from solution (after 6 h shaking at 25°C) was considered as adsorbed (retained) Mn. The adsorption data showed a highly significant fit to Freundlich and also to the two‐surface Langmuir adsorption isotherms. The coefficients of both isotherms showed significant positive correlations with cation exchange capacity (CEC), organic matter (OM), and CCE of the soils indicating that OM and calcium carbonate are the sites of Mn retention in calcareous soils. Comparison of the adsorption data of this experiment with those of plant Mn uptake of the same soils (published earlier) shows that as the Langmuir second surface adsorption maxima (maximum retention capacity) of the soils increase the plant Mn concentration and uptake decrease.

Synergistic effects of elemental sulfur and synthetic organic conditioner amendments on selected chemical properties of calcareous soils

This study evaluated the combined effects of elemental sulfur (ES) and synthetic organic conditioner (SOC) amendments on the chemical properties of calcareous soils from arid and semiarid regions. A 60‐day laboratory incubation experiment was conducted to determine if amending ES‐treated soils with SOCs would improve selected chemical properties such as pH and soluble and extractable nutrients. Four calcareous soils from central Saudi Arabia varying in CaCO3 content were used. Air‐dried soil samples were treated with (1) ES at rates of 7.7,14.8, 23.7, and 19.0 g kg−1 to neutralize 50% CaCO3 content of soil 1, soil 2, soil 3, and soil 4, respectively; (2) four SOCs— Broadleaf(BL), Aquasorb (AS), Agrihope (AH), and Hydrogel (HG)‐at a rate of 02% (dry weight basis). The addition of ES or ES + individual SOC amendments improved some of the soil chemical properties. In all cases, addition of ES + SOC was more effective than ES alone as determined by a decrease in soil pH and an increase in soluble SO4 2‐ and Na+, as well as extractable Fe and Mn. Addition of ES alone was more effective than ES + SOC only in increasing soluble Ca2+ and Mg2+. In contrast, the addition of an individual SOC adversely affected soil properties, resulting in an increase in soil pH and soluble Na+ and decreases in soluble Ca2+ and Mg2+ and extractable Zn, Fe, and Mn. Extractable Cu and P were not affected by the changes in soils chemistry induced by the treatments. Soluble K concentrations were significantly high in all soil samples treated with the HG conditioner and ES + HG. The deleterious effects by individual SOC on selected soil chemical properties indicates the potential adverse effect by these conditioners on calcareous soils. Nevertheless, the addition of ES in conjunction with SOC was generally synergistic and improved soil properties.

Extractability of previously‐applied zinc as influenced by properties of calcareous soils1

The recovery of applied zinc (Zn) by plants is relatively small. Coupled with lack of leaching, this leads to accumulation of Zn in topsoil which may result in unfavorable growth conditions for the subsequent plants. Different extractants may be used for assessing the Zn status of soils previously treated with Zn sources. The extractability of retained Zn is influenced by soil properties. This experiment was conducted to study the influence of selected properties of calcareous soils on extractability of Zn by three popular Zn soil tests. Twenty samples from surface horizons (0–20 cm) of highly calcareous soils of southern Iran (pH 7.9 to 8.5; calcium carbonate equivalent 16 to 58%) previously treated with three levels of Zn (0, 10, and 20 mg Zn kg‐1 soil as ZnSO4#lb7H2O) in triplicate and under one crop of corn (Zea mays L.) were extracted with DTPA, EDTA‐(NH4)2CO3 and Na2‐EDTA. Extractability (EXT) in a particular extractant was defined as the slope of the regression line, relating extractable Zn of each soil to the rate of applied Zn, multiplied by 100. The EXT values of soils ranged from 24.9 to 73.0% for DTPA, 47.2 to 84.4% for EDTA‐(NH4)2CO3, and 28.2 to 56.7% for Na2‐EDTA. Stepwise regression equations showed that cation exchange capacity (CEC) and calcium carbonate equivalent (CCE) followed by clay content were the most influential soil properties in EXT of retained Zn of highly calcareous soils. The EXT values decreased with increase in CEC, and CCE but increased with increase in clay.

Effects of the application of pig slurry on some physico-chemical and physical properties of calcareous soils

The effects of adding pig slurry to two calcareous soils containing different levels and types of clay were studied over a period of two years. Doses up to 1000 m 3 ha −1 year −1 were used and the evolution of some physico-chemical (cationic exchange capacity and pH) and physical (porosity and water holding capacity) properties was studied. The exchange capacity increased as more slurry was added when the soil had a low clay content, giving rise to a good correlation between the values for organic carbon and exchange capacity. In soils of a higher clay content, the increase in exchange capacity was not so significant. pH decreased with the addition of slurries, possibly due to the liberation of exchangeable ammonium and its subsequent nitrification.

Phosphorus sorption and availability indices as affected by properties of calcareous soils

Abstract The Olsen solution is usually considered the best extractant for estimating P availability in calcareous soils, but predictability of the response to P fertilizers is often low under field conditions. In this study, soil characteristics influencing P sorption and extractability were evaluated. Forty‐one soils varying in CaCO3, pH, and clay content were selected from pastures to minimize the effect of recent P additions. A P sorption index (PSI) determined from a single addition of 150 mg P/100 g soil was related to soil Ca and CaCO3, but the correlation coefficients were rather low (r = 0.46 and 0.38, respectively). A P availability index (PAI), determined from the increase in extractable soil P after adding 50 mg P/kg to a suspension and allowing it to dry, was correlated quite well with cation exchange capacity and clay content (r = ‐0.61 for each) in soils with pH < 8.8. The PAI also had a positive relationship with the density of the processed soil sample (r = 0.60). The relationship between ...

Effect of elemental sulphur on some properties of calcareous soils and growth of date palm seedlings

Abstract Seedlings of date palm (Khlas cultivar) were grown in two soils with similar contents of CaCO3 and different clay contents. After addition of farmyard manure, elemental sulphur was added to both soils at rates of 0, 500, 1000, 2000, 5000, 10000, 20000 and 30000 μg S0 g−1. After five months, height, fresh and dry weight of plants were measured, and leaf contents of N, S, P and micronutrients were determined. Soil pH and contents of CaCO3, soluble salts and available P and micronutrients were determined. The results showed that the content of CaCO3 and pH values decreased with an increase in S0, and salinity was increased. This effect was more pronounced in soils containing less clay. Availability and uptake of P, Fe, Mn, and Zn were increased at high addition rates of S0. Growth of seedlings was reduced at S0 rates over 5000 μg g−1, possibly due to the salinity and imbalance between N and S.