scholarly journals KAJIAN SIFAT FISIKA EMPAT TANAH UTAMA DI SUMATERA BARAT

Jurnal Solum ◽  
2007 ◽  
Vol 4 (2) ◽  
pp. 81
Author(s):  
Yulnafatmawita Yulnafatmawita ◽  
Asmar Asmar ◽  
Ari Ramayani

A research about soil physical study of four main soils found in West Sumatra was conducted in 2006.  The research was aimed to determine some soil physical properties of four soil which are mostly found in West Sumatra.  The four soil orders assessed were Ultisol from Agricultural Expreriment Station Limau Manis, Oxisol from Lubuk Minturun, Entisol from Tabing Kecamatan Koto Tangah Padang, dan Andisol from Bukik Gompong Kabupaten Solok.  The result showed that at the depth of 0-20 cm soil profile.  Ultisol and Oxisol had finer texture than those of Andisol and Entisol.  Andisol was dominated by silt while Entisol was dominated by sand particles.  Andisol had the lowest bulk density and the highest soil organic matter and total porosity.  Soil Organic matter content of Entisol, Oxisol, and Ultisols was low in criteria.  Plant available water (PAW) was higher in Oxisol, then followed by Andisol, Ultisol, and Entisol.Key words: Organic matter, bulk density, texture, porosity, plant available water

Author(s):  
Biboss Maharjan ◽  
Anon Chaulagain ◽  
Parikrama Sapkota ◽  
Dhurva P. Gauchan ◽  
Janardan Lamichanne

 The aim of this study was to investigate the response of soil physical and chemical properties during the transition from conventional to organic farming system. Soil samples were collected from five different farms: “Hasera organic farm” under 10 years of organic farming, “Everything organic nursery” under 5 years of organic farming, “Grameen Krishi” under 3 years of transition from conventional to organic, “Gautamshree farm” under 1 years of transition from conventional to organic and “Kuntabeshi farm” under IPM practice as reference. Soil bulk density, moisture content, texture, NPK, CEC and soil organic matter was evaluated in soil samples collected at 0-15 cm. Soil organic matter (5.45%) was highest in Hasera farm, whereas lowest bulk density (1.02gcm-3) was also in Hasera farm. Lowest soil organic matter content was found in Gautamshree farm. Soils of all farms were under loam texture. Soil macronutrients were highest in Grameen Krishi farm. The overall pH value of all soil samples was slightly acidic to acidic.Kathmandu University Journal of Science, Engineering and TechnologyVol. 13, No. 1, 2017, Page: 76-84


1986 ◽  
Vol 66 (4) ◽  
pp. 743-746 ◽  
Author(s):  
D. A. ANGERS ◽  
R. R. SIMARD

As a part of a study on soil compaction, measurements of soil bulk density were taken three times during the season at five sites and three depths. Strong negative correlations were obtained between soil organic matter content and (1) soil bulk density and, (2) the increase in bulk density during the season. Key words: Bulk density, compaction, organic matter


1960 ◽  
Vol 11 (6) ◽  
pp. 902 ◽  
Author(s):  
JS Russell

Variously treated grassland plots at the Kybybolite Research Centre established in 1919 on solonetzic soils were sampled in 1957–58. Analyses of the soils and for pH and nitrogen were made and compared with earlier analyses made in 1938. Bulk density and organic carbon were also determined. Treatment with phosphorus fertilizers and grazing with sheep has resulted in large increases in the organic matter content of the surface soil. A large part of the increase has been concentrated in the 0–2 in. horizon. At the 6–8 in. level, increases have been small. When considered on the basis of pounds per acre, the increase in soil nitrogen in the surface 6 in. of some plots appears to be linear with time, and even after 39 years shows no signs of approaching an asymptotic value. However, there appears to be differential behaviour within the soil profile. The rate of increase of the 0–2 in. horizon in recent years shows signs of being much less than in the earlier years of the experiment. On the other hand, in the 2–4 and 4–6 in. horizons the recent rate of increase is similar to or greater than that in earlier years, which indicates that a deepening of the organic matter profile is occurring. There appears to be some relation between the increase in soil nitrogen and sheep-carrying capacity. The increase in soil nitrogen on the soils from the plots has been, on the average, equivalent to 14 lb of soil nitrogen per sheep per acre per year. Additional calcium applied with water-soluble phosphorus appears to result in higher levels of soil organic matter. Lime, in particular, appears to result in the highest levels of soil organic matter. Analysis of the soils shows that the increase in soil organic matter is associated with a slight decrease in pH. The soils also show a decrease in bulk density which is closely related to changes in organic matter content. Various aspects of organic matter accumulation are discussed, particularly the importance of the time factor in this process and the lack of a causal relationship between the amount of superphosphate applied and the increase in organic matter.


2020 ◽  
Vol 117 (3) ◽  
pp. 351-365
Author(s):  
J. Pijlman ◽  
G. Holshof ◽  
W. van den Berg ◽  
G. H. Ros ◽  
J. W. Erisman ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1326
Author(s):  
Calvin F. Glaspie ◽  
Eric A. L. Jones ◽  
Donald Penner ◽  
John A. Pawlak ◽  
Wesley J. Everman

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.


2021 ◽  
Vol 13 (7) ◽  
pp. 3957
Author(s):  
Yingying Xing ◽  
Ning Wang ◽  
Xiaoli Niu ◽  
Wenting Jiang ◽  
Xiukang Wang

Soil nutrients are essential nutrients provided by soil for plant growth. Most researchers focus on the coupling effect of nutrients with potato yield and quality. There are few studies on the evaluation of soil nutrients in potato fields. The purpose of this study is to investigate the soil nutrients of potato farmland and the soil vertical nutrient distributions, and then to provide a theoretical and experimental basis for the fertilizer management practices for potatoes in Loess Plateau. Eight physical and chemical soil indexes were selected in the study area, and 810 farmland soil samples from the potato agriculture product areas were analyzed in Northern Shaanxi. The paper established the minimum data set (MDS) for the quality diagnosis of the cultivated layer for farmland by principal component analysis (PCA), respectively, and furthermore, analyzed the soil nutrient characteristics of the cultivated layer adopted soil quality index (SQI). The results showed that the MDS on soil quality diagnosis of the cultivated layer for farmland soil included such indicators as the soil organic matter content, soil available potassium content, and soil available phosphorus content. The comprehensive index value of the soil quality was between 0.064 and 0.302. The SPSS average clustering process used to classify SQI was divided into three grades: class I (36.2%) was defined as suitable soil fertility (SQI < 0.122), class II (55.6%) was defined as moderate soil fertility (0.122 < SQI < 0.18), and class III (8.2%) was defined as poor soil fertility (SQI > 0.186). The comprehensive quality of the potato farmland soils was generally low. The proportion of soil nutrients in the SQI composition ranged from large to small as the soil available potassium content = soil available phosphorus content > soil organic matter content, which became the limiting factor of the soil organic matter content in this area. This study revolves around the 0 to 60 cm soil layer; the soil fertility decreased gradually with the soil depth, and had significant differences between the respective soil layers. In order to improve the soil nutrient accumulation and potato yield in potato farmland in northern Shaanxi, it is suggested to increase the fertilization depth (20 to 40 cm) and further study the ratio of nitrogen, phosphorus, and potassium fertilizer.


2005 ◽  
Vol 35 (9) ◽  
pp. 2178-2187 ◽  
Author(s):  
J C Neff ◽  
J W Harden ◽  
G Gleixner

Boreal ecosystems contain a substantial fraction of the earth's soil carbon stores and are prone to frequent and severe wildfires. In this study, we examine changes in element and organic matter stocks due to a 1999 wildfire in Alaska. One year after the wildfire, burned soils contained between 1071 and 1420 g/m2 less carbon than unburned soils. Burned soils had lower nitrogen than unburned soils, higher calcium, and nearly unchanged potassium, magnesium, and phosphorus stocks. Burned surface soils tended to have higher concentrations of noncombustible elements such as calcium, potassium, magnesium, and phosphorus compared with unburned soils. Combustion losses of carbon were mostly limited to surface dead moss and fibric horizons, with no change in the underlying mineral horizons. Burning caused significant changes in soil organic matter structure, with a 12% higher ratio of carbon to combustible organic matter in surface burned horizons compared with unburned horizons. Pyrolysis gas chromatography – mass spectroscopy also shows preferential volatilization of polysaccharide-derived organic matter and enrichment of lignin- and lipid-derived compounds in surface soils. The chemistry of deeper soil layers in burned and unburned sites was similar, suggesting that immediate fire impacts were restricted to the surface soil horizon.


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