Among the large number of vegetation and salinity indices that have been developed for salinity detection in recent years, four vegetation indices NDVI, EVI, SAVI, and GDVI and four salinity indices SI-1, SI-2, SI-3, and BI, which had the best performance based on the results of the previous papers, were selected (Table 1). From selected indices, the following criteria were used to choose the best salinity indicators in the study area: (a) correlation coefficient, (b) mean of standard deviation, and (c) trend line slope of the mean index. In the next step, evaluating the variation of salinity indicators in different months of the year from January to December should be carried out to select the best time for trend analysis of soilsalinity. To this purpose, four years analysis of monthly changes from April 2013 to December 2016 was performed using Landsat 8 images. The month which has the most increase in salinity indices values in bare soils and the most reduction in vegetation indices values in vegetation lands is considered the optimal time to assess changes due to more sensitivity to salt features of two land cover types over years. In this regard, images of late May were selected. Finally, slope map of optimal VI/SI indices of May images during 2000 to 2016 is created using Landsat7, 8 data to assess the rate of change for each pixel through salinity indicators. The slopes with greater absolute values, indicate large amounts of changes in both land cover pixels due to salinity occurrence and correspond to highly salt affected soils over the years of study. The areas with fewer slope values represent unchanged pixels and correspond to normal or slightly affected soils. According to this, the study area was divided into different degrees of salinity which are: (1) non- saline, (2) slightly saline, (3) moderately saline, and (4) highly saline. In addition to thresholding, K-means clustering method is also applied to segment the slope image map of both land cover types to different salinity classes. The results of obtained salinity classes of both methods were compared with each other to assess the effectiveness of used methods and the extent of salinity hazard in the study area during the last two decades.
Complete information on physical and chemical properties of soils found in NAD and Nias island, could be seen in Table 5. In Banda Aceh and the surrounding areas, alluvial soils in land system PTG had soil texture in topsoil categorized as loam, sand and loamy sand. Soil ripeness at topsoil were categorized as unripe, half ripe and ripe. This layer had acid soil pH, and was slighlty alkaline, and there was no potential for pyrite. Soilsalinity was categorized as ranging from very low to very high (0.447 – 7.22 ms/cm). The texture of subsoil were loam and silty loam. Soil ripeness were categorized as unripe, nearly ripe and ripe. There was no pyrite potential; On the other hand, soil pH was categorized as slighly acid, neutral and alkaline (6.32 – 7.92). Salinity was categorized as ranging from very low to very high (0.388–7.75 ms/cm), and total soil N were categorized as very low and very high (0.06 – 2.39%).
(Deverel et al., 1994), a concentration that poses a potential health threat to humans, livestock, and wildlife. Classic symptoms of Se toxicity include nervous system dysfunction (e.g. ‘blind staggers’ in ruminants), skin lesions, and nail necrosis (Mayland, 1994). Plant Se concentrations are infl- uenced by the plant species and by numerous soil factors, including the form and concentration of Se in the soil, soil pH, clay content, soilsalinity, and the concentration of competitive ions (e.g. SO 4
Isolation and characterization of humic acid of various waste matterials aimed to assess the its quantity and quality. The improvement potentcy of soilsalinity and plant growth is needed to be studied further. Humic acids extracted from sewage plants, livestock and industry with 0.5 N NaOH (1:10) for 24 hours and precipitated approximately 12 hours to separate the humic and humin. Humic material containing humic acid and fulvic acid. Precipitation of humic acid with the addition of 5 N HCl to pH 2, then centrifuged at 200 rpm 30 minutes. Humic acid purification by washing with HF + HCl 1: 3 followed by water up to 3 times. Pure humic acid is dried at a temperature of about 40oC, and then characterized the value of E4/E6, C-organic, EC, pH and humic%. E4/E6 ratio values <5 shows the character of humic acid. Humic acid levels are best obtained from peat followed by coal, compost, filter cake, and manure. Cation exchange capacity in the range of 80-115 g me/100 humic acid at a pH between 6.7-7.5. EC humic acid 0 ms /cm. Humic acid potential in reducing salinity and the growth of rice for 35 DAP was not significantly different between the kinds of waste.
horizon followed by decrease with depth can be attributed to flooding with saline water or accumulation of salts through upward capillary movement of saline ground water. Soilsalinity of different horizons ranges from 2.4 to 3.4 dS/m at Asasuni and 3.1 to 4.0 dS/m at Kalapara in December (2008) (Table 5). In dry season, this range, however, becomes 9.2 to 10 dS/m at Asasuni and 6.9 to 8.2 at Kalapara, which is under saline category according to soil report of (BARC 1990) and (SRDI 2003). Zaman and Bakri (2003) reported that Bangladesh had 3 million hectares of land affected by salinity, mainly in the coastal and south-east districts, with ECe values ranging between 4 and 16 dS/m.
This study was conducted to determine the effect of initial soilsalinity and salinity levels of irrigation water on total tuber yield and tuber size distribution under subirrigation. There was no significant effect of initial soilsalinity or subirrigation water salinity on the performance of Kennebec or Russet Burbank cultivars. Significant inhibitory effects of salinity on Norland cultivar indicate that some cultivars can be affected by saline soil±water system under subirrigation. However, successful production of potatoes with brackish water having salinities from 1 to 9 dS/m indicates the possibility of using brackish water having salinity even higher than this. Subirrigation systems may prove to be quite useful for food production with poor quality irrigation water in the areas where monsoon rains can flush-out salts accumulated in the crop root zone. The system will also be sustainable if good quality water for surface irrigation is available at some other time during the year.
The advantages of aero-space remote sensing techniques using optical sensors for non-destructive spatial assessment of soils characteristics have been recognized. Various researchers in recent past showed the potential utility of imaging spectrometry based remote sensing technique for spatial estimation of soil properties (reviewed by Ben-Dor et al., 2008). However, limited research studies have been carried out showing the potential of microwave remote sensing data for spatial estimation of various soil properties except soil moisture. This paper reviews the status of microwave remote sensing techniques (active and passive) for spatial assessment of soil quality parameters such as soilsalinity, soil erosion, soil physical properties –soil texture & hydraulic properties; drainage condition; and soil surface roughness.
organic household waste and the use of new composting technologies have improved the compost quality (Ammar, 1996) and increased the amount of compost in some European countries. Therefore compost may be used not only in agriculture, horticulture, landscape conservation and reclamation of mining areas but also for amelioration of degraded forest soils (Borken and Beese, 2000). Guerrero et al. (2000) found increased bacteria and fungal popula- tions and improved stability of soil aggregates when municipal solid waste compost was applied to burnt forest soils. The authors pointed out that compost addition is a suitable technique for accelerating the natural recovery process of burnt soils. However, the release of nutrients and the effect on the autochthon microbial community of forest soils may vary with the maturity, chemical composi- tion and amount of compost. Certainly, the microbial community of compost and forest soils is different and, therefore, the competition between species may affect the decomposition of organic matter.
The maps published by RePPProT (Regional Physical Planning Project for Transmigration) that were used included: Present Land Use and Land Status, and Land System and Land Suitability. The main ones used as reference for the peat distribution map of Sumatra (1990) and Kalimantan were the Land System and Land Suitability maps on a scale of 1:250,000. A desk study was made of these maps (80-90% took the form of analysis of remote sensing and other supporting data), supplemented by field verification data (10-20%). These maps, together with geological and soil maps/data, were used as input for the analysis of satellite images in order to identify the distribution of peatlands. However, if while analyzing the image of a particular site it was known for certain (from previous surveys to that area) that the site did in fact comprise peatland, even if this contradicted the RePPProT map, it was identified as peatland. The RePPProT maps used are presented in Table 5, Table 6, and Figure 4.
and found that increased labile carbon was resulted from the growth and decomposition of organic materials. Plant roots could break down the carbon compound into labile carbon (Conteh et al., 1997). Labile carbon function as the source of energy for the growth of soil microbes that is important for development of soil microbes population and influence the rate of organic material decomposition. This condition was supported by the average microbial respiration which increased significantly under the organic farming system (Table 1). Soil microbial respiration rate indicates the activities of microbes in the soil (Cong-Tu et al., 2006). Soil organic carbon is positively correlated with labile carbon and soil respiration rates. In fact labile SOC, not total SOC, mainly controls soil respiration (Wang et al., 2013). These correlations occurred due to the labile carbon is part of total soil organic carbon (Binoka, 2008). Moreover, the labile carbon is active, therefore it is easily driven down to the deepen part of soil profile. Result of this present study also showed that SOC was consistently higher at different soil depths (0-10 cm, 10-20 cm and 20-30 cm) but the highest (2.85%) was found at 10-20 cm depth (Figure 4). Komatsuzaki & Syuaib (2010) reported the highest (2.89%) SOC in the top 10 cm soil depth of organic compared to conventional rice field. Soil bulk density under organic system was not significantly different from that under its conventional counterpart. This was due to organic fertilizers that are usually applied by vegetable farmers in the conventional system although only in small amounts.
Abstract To assess the recovery trajectory and self- maintenance of restored ecosystems, a successional gradi- ent (1, 3, 5, 15, and 30 years after abandonment) was established in a sub-alpine meadow of the eastern Tibetan Plateau in China. Plant communities and soil carbon and nitrogen properties were investigated and analyzed. Regression analyses were used to assess the models (linear or quadratic) relating measures of species richness, soil carbon and nitrogen properties to fallow time. We found that species richness (S) increased over the first 20 years but decreased thereafter, and aboveground biomass showed a linear increase along the fallow time gradient. The rich- ness of different functional groups (forb, grass and legume) changed little along the fallow time gradient, but their corresponding above ground biomass showed the U-shaped, humped or linear pattern. Soil microbial carbon (MBC) and nitrogen (MBN) in the upper 20 cm showed a U-shaped pattern along the fallow time gradient. However, soil organic carbon (C org ) and total nitrogen (TN) in the
This chapter briefly explains the grounding system in term of different soil layers and the effects to the soil resistivity. This can be referred from literature reviews from journal published. In addition, this chapter will present terms including, soil resistivity, grounding impedances, earth potential and method that can be used to examine the soil resistivity.
Total C, N and 15 N in the whole soil, taken from microplots amended with labelled cattle slurry and from main plots with or without cattle slurry, were determined in samples taken initially, in spring and at harvest using an ANCA-MS system (ANCA-SL elemental analyzer and 20–20 mass spectrometer, Europa Scientific Ltd., Crewe, UK ).
Good environmental condition supported by sufficient feeding and provision of good container with optimum salinity can increase the production output. This research aimed to obtain information about the relationship of salinity with growth of sinodontis. The fry that used have average length of 3,41+0,04 cm with average weight of 0,60+0,02 g which comes from Cibinong, West Java. The fry first adapted into aquarium and next treated on 0, 2, 4 and 6 treatment with 3 repetitions. Containers used for the treatment are 12 aquariums which have dimension of 30x25x25 cm3. Each one is filled with 15 liters of water. The length of time for the development of the fish is 28 days. During the period of time, the fish were fed with silkworm twice a day in the morning and in the afternoon in at satiation. Water replacement is 75% volume per day. Salinity treatment significantly affects (P<0,05) length growth rate (LPP), weight growth rate (SGR), and feed efficiency (EP). Treatment with 2 ppt salinity showed the best production performance.
Perubahan penggunaan lahan dari ekosistem alami menjadi lahan pertanian akan mempengaruhi kondisi fisik suatu tanah. Hal ini sehubungan dengan perubahan kandungan bahan organik tanah, salah satu agen pengikat dan pemantap struktur tanah. Perbedaan intensitas pengolahan tanah terhadap suatu areal dalam mempersiapkannya menjadi lahan pertanian akan menyebabkan kehilangan bahan organik yang berbeda serta derajat kehancuran aggregat yang berbeda pula. Penelitian ini bertujuan menganalisis status C-organik dan distribusinya dalam aggregat dari 2 jenis tanah akibat perubahan penggunaan lahan. Sampel tanah yaitu Oxisol (Ferrosol=ASC) didominasi oleh liat kaolinit dari Lamington dan Vertisol (Vertosol=ASC) didominasi oleh liat montmorillonit dari Goondiwindi, Queensland Australia. Kandungan C-organik, N total, C/N ratio dianalisis dari aggregat tanah alami dan aggregat yang difraksionasi. Perubahan penggunaan lahan dari hutan hujan tropis menjadi padang rumput pada Oxisol menurunkan C-organik tanah dari 6.9 menjadi 5.6%, N total dari 0.63 menjadi 0.53% tetapi tidak nyata mempengaruhi C/N rationya. Sedangkan pada tanah Vertisol, C-organik menurun dari 2.0 menjadi 1.2%, N total dari 0.21 menjadi 0.15%. Akan tetapi perubahan penggunaan lahan untuk kedua tanah tidak merubah pola distribusi kandungan C-organik dan N total tanah. Key words: land use change, soil organic carbon (SOC), fractionated soil aggregate, energy input, degradation