Soil fertility changes in a red-brown earth under irrigated pastures. I. Changes in organic carbon/nitrogen ratio, Cation exchange capacity and pH

1966 ◽  
Vol 17 (3) ◽  
pp. 317 ◽  
Author(s):  
AJ Rixon

Organic matter and soil fertility changes under irrigated pastures were followed for 5 years at Deniliquin, N.S.W. The effects of three annual pastures and of three perennial pastures were studied. Four years after their establishment an organic matter layer (mat) had formed under all pastures, and after its formation there was no further accumulation of organic carbon in the 0–3 in. soil horizon. The mean annual increase in organic carbon was 625 lb/acre under annual pastures and 1146 lb/acre under perennial pastures. The carbon/nitrogen ratios of both soil and mats, and the relationships of both organic carbon and nitrogen to the cation exchange capacity of the mats, were similarly affected by the annual and perennial pastures. The heterogeneous nature of the mats obscured any differences in their carbon/nitrogen ratios, which ranged from 12.8 to 22.0. The cation exchange capacity of the 0–3 in. soil horizon remained unchanged. The cation exchange capacity of the organic matter of the mats was approximately 100 m-equiv./100 g. After mat formation the underlying soil had a pH of approximately 6.0 under clovers and 6.5 under ryegrasses. The pH values of the mats ranged from 5.9 to 6.6.

1930 ◽  
Vol 20 (3) ◽  
pp. 348-354 ◽  
Author(s):  
W. McLean

1. The average carbon-nitrogen ratio for fifty British soils from widely distributed areas approximates to the figure 10: 1 given by other investigators. The range of variation is from 6·5 to 13·5: 1. Sixteen foreign samples gave C/N ratios varying from 2·0 to 23·0: 1.2. Soils from limited areas, whether high or low in organic carbon, give approximately constant ratios, but these ratios vary from place to place according to soil, climate, etc. It is suggested that the C/N ratios may be specific.3. The C/N ratios of arable soils do not differ appreciably from those of grassland soils. The percentages of carbon and nitrogen are somewhat higher in the grassland samples than in the arable samples.


2019 ◽  
Vol 24 (1) ◽  
pp. 35-53
Author(s):  
Kathleen Cedeño

Soil quality is crucial to global food production security. However, research data on soil quality, which is vital to enhancing soil fertility and crop yield, is limited particularly on the soil in the rice fields located in Langkong, Mlang, Cotabato. This study aims to assess the soil quality of one of the organic rice farms in said area. Soil samples were collected in thirty-one (31) paddies for two sampling periods: thirty (30) days after harvest and thirty (30) days after rice transplanting. Eight (8) soil indicators representing soil physicochemical characteristics were measured from 0-15 cm depth; the indicators were soil texture, water holding capacity, pH, exchangeable phosphorus, extractable potassium, total organic matter, electrical conductivity, and cation exchange capacity. Results reveal that soils in the studied area are characterized by clay loam with moderate water-holding capacity of about 62.57% and 60.57% for both sampling periods, respectively. The soil is strongly acidic (5.3 and 5.5) and has a low amount of organic matter (2.16% and 1.57%) and exchangeable P (8.55 ppm and 2.48 ppm), although it has marginal extractable K (80.77 ppm and 91.10 ppm). Also, the soils are non-saline and have low cation exchange capacity. The findings signify that the soils have insufficient fertility to sustain the optimal growth of the rice plants which can potentially reduce the yield of rice production. Thus, amendment of the soil quality and enhancement of soil management practices should be taken into consideration to further improve soil fertility to ensure productivity and profitability of farmers.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan


2021 ◽  
Vol 23 (3) ◽  
pp. 368-374
Author(s):  
A. BASUMATARY ◽  

Two hundred fifty geo-referenced surfaces (0-15 cm) soil samples were collected and analysed for macronutrients and micronutrients to study fertility status in soils of Dima Hasao district of Assam and their relationship with some important soil properties. Soils of the district were found to be extremely acidic to slightly acidic in reaction with a low to high organic carbon content and low in cation exchange capacity. The soil of the district indicated that the available nitrogen, phosphorus and potassium status was observed to the tune of 14.0 %,7.2% and 67.2% under low and 86.0 %, 92.8 % and 32.8 %under medium categories, respectively. The overall percent deficient of exchangeable calcium, magnesium and available sulphur in soils was 25.6, 30.4 and 6.8 %, respectively. Based on critical limit, all soils were adequately supplied with DTPA-extractable Fe, Mn and Cu content. In respect of zinc and boron, soils exhibited 90.4 and 73 per cent under sufficient, while, 2.4 and 12 per cent were found deficient in DTPA -Zn and HWS-B, respectively. Soil pH and EC showed positive correlation with macro nutrients and negative correlation with micronutrients. The macro- and micronutrient showed significant positive relation with soil organic carbon and cation exchange capacity.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Martin Leue ◽  
Daniel Uteau ◽  
Stephan Peth ◽  
Steffen Beck‐Broichsitter ◽  
Horst H. Gerke

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.


2012 ◽  
Vol 500 ◽  
pp. 142-148 ◽  
Author(s):  
Wen Xing Lü ◽  
Hong Jiang Zhang ◽  
Yu He Wu ◽  
Jin Hua Cheng ◽  
Jian Qiang Li ◽  
...  

Through the research and sampling analysis on different plant hedgerow in sloped farmland in Three Gorges reservoir area, we will conduct research on the impact of plant hedgerow in Three Gorges on the chemicophysical properties of soil and soil erosion. The results show that the plant hedgerow mainly composed by Morus alba, Citrus reticulata, Zanthoxylum bungeanum, Vitex negundoand Begonia fimbristipula can decrease the soil density as well as sand content and increase soil porosity, soil water content, silt content and clay content to some extent. The organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil in different locations in plant hedgerow indicate as maximum in on-band, minimum in inter-band, middle both upper-band and below-band. In the same slop with no plant hedgerow, the organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil show a trend of increasing from the top to the bottom of the slop, which reveals that these substances own a feature of accumulation by moving to the bottom. The strength of soil anti-corrosion in different plant hedgerow is: Vitex negundoand (79.2%)> Citrus reticulata (36.4%)> Morus alb (22.4%)> Zanthoxylum bungeanum (18.9%)> Begonia fimbristipula (15.3%)> CK (8.7%), and the soil anti-corrosion indices in plant hedgerow are decreasing with the increase of soil immersion time, besides, the former and the latter are 3 times polynomial function. For those 5 plant hedgerows, Vitex negundoand owns the best impact on improving soil chemicophysical properties and reducing soil erosion.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


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