Moisture retention and release characteristics of some soils developed on different parent materials and landforms

Abstract Ten soils developed under different landforms and parent materials in a micro-watershed of Wunna catchment were studied for soil properties and also for moisture retention and release characteristics. These soils show considerable variations in physical and chemical characteristics and also in retention and release of soil water. The variation in the amount of water retention of soils on basalt as well as sandstone are attributed to relative proportion of soil separates and type and amount of clay minerals. The water holding capacity of heavy textured soils are more as compared to light textured soils. The plant available water capacity of soils on basalt is relatively higher as compared to soils on sandstone indicating high amount of water storage in the profile during crop growth. The per cent moisture release was maximum between soil matrix suction of 33 kPa and 500 kPa of basaltic soils (73 to 82 %) as well as sandstone soils (65 to 87 %). The percent moisture release decreased nearer to wilting point. The release of soil moisture is gradual between 33 to 1000 kPa matric suction in case of soils on basalt. But in case of sandstone soils, sudden release is observed between 33 to 500 kPa and therefore sandy soils show moisture stress during crop growth. The study indicates that the rate of release of moisture in fine textured soils is more gradual than the relatively coarser textured ones

Ecological and Economic Potential of Major Halophytes and Salt Tolerant Vegetation in India

Soil salinization is a global and climatic phenomenon that affects various spheres of life. The present rate of salinization is perilously fast because of global climate change and associated events leading to enhanced land degradation, loss of soil fertility and crop productivity. In this chapter, we tried to focus on the arid and semiarid regions of India along with our coastal zone which are economically fragile regions and need much closer attention. In future, India will face extreme pressure on its land resources in agriculture because of likely rapid degradation of these resources. Thus, salt affected soils must be brought under cultivation by adopting site specific strategies to ensure national food and nutritional security. In this regard, a comprehensive review of the major halophytes of these ecological zones, its mechanism of salt tolerance, ecological and economic potential is done. The potential applications of saline land vegetation including halophytes in climate change mitigation, phytoremediation, desalination, food, secondary metabolite and nutraceutical production, medicine, and saline agriculture have been discussed. Further, we tried to focus on popular farmer adopted halophytic species including edible ones, their uses, products of economic significance etc. which is highly imperative for effective utilization of these saline soils leading to improved livelihood and sustenance of resource poor farmers along with improved ecological balance

Not Available

Not AvailableThe Gujarat state is sharing the longest coastal line in the country i.e. 1600 km. Salinity problems are increasing at an alarming rate, more particularly in the irrigation command areas and coastal area. Out of 67.40 lakh hectares area affected by coastal and inland soil salinity/sodicity in the country, Gujarat has the largest salt-affected lands (21.05 lakh ha) which include 4.62 lakh ha coastal saline soils, 10.98 lakh ha inland saline soils and 5.45 lakh ha inland alkali soils. It is reported that Gujarat, in general received less rainfall during the period 1960–1990 compared to 1991–2008 and in particular Bharuch district received average annual rainfall of 753 mm during 1975-2011 as compared to 895 mm for the period 2000-2011. The average annual rainfall during the period 2000-2011 was increased by 19 per cent over long term average (1975-2011). It is also observed that the intensity of rainfall was more during later period of monsoon for 2000-2011 as compared to 1975-2011. Considering the climatic and edaphic factors, crops traditionally cultivated in Gujarat were highly appropriate. In Gujarat state the soils are ranging from sandy and saline to deep black clayey. Sand to sandy loam and saline soils are confined to the Kutch agro-climatic region and North Gujarat and partly to North Saurashtra. The soils predominantly found in Kutch are sandy and saline and receives the lowest rainfall in the state (346 mm per annum). The crops that have been traditionally cultivated in Kutch include pearl millet and sorghum. North Saurashtra has two dominant soil types: shallow to medium black and shallow to medium black calcareous. The average rainfall is about 633 mm per annum. While parts of North Saurashtra have medium black and poorly drained soils, South Saurashtra is completely covered with shallow to medium black calcareous soils. The average rainfall here is 877 mm per annum. Groundnut, sorghum, and pearl millet are the crops traditionally grown in South Saurashtra. Central Gujarat is covered with deep, medium black to loamy sand and sandy loam to sandy soil and average rainfall has been recorded at 822 mm per annum. The traditionally cultivated crops here are rice and cotton. South Gujarat, along with Southern Hills, characteristically comprises deep black clayey and deep black with coastal alluvial to medium black soils while the northern most region of South Gujarat is home to deep black to medium black poorly drained to loamy soils. The average rainfall in South Gujarat and the Southern Hills is 1207 mm per annum and 1819 mm per annum, respectively. The crops traditionally grown here include cotton, rice and sorghum. Gujarat witnessed an increase in groundwater extraction for irrigation purposes over the past two decades. This has been mainly caused by the shift in cropping patterns towards water intensive crops such as wheat, sugarcane, rice, and cotton. Seawater ingress besides marine influence creates huge salinity in the coastal regions. Salinity in coastal soils, unlike that in inland soils is caused during the process of their formation under marine influence and subsequently due to periodical influence of saline water either through inundation or capillary rise from shallow undergroundwater or saline water irrigation. Dominant salts occur in coastal saline soils are sodium chloride and sodium sulphate with loads of soluble cations with dominance of Na followed by Mg, Ca and K and chloride as the predominant anion followed by sulphate. The coastal land needs protection against tidal inundation through protective embankment like bio-shield for control of sea ingress, soil erosion and salinity. Monsoonal rainfall intensity has been increased during later period of Monsoon in the western coastal region. Unsuitable climatic conditions, soil and water degradation, marine influence in the coastal areas and secondary salinisation in irrigation command areas decreased the productivity of arable farming. Technological knowledge generated till date has helped in solving the problems in large tracts of land in different regions to restore their full productive potential. However, new challenges either due to changing climate or land use anomalies, leading to exponential increase in the area under salinity. With new challenges cropping up, soil salinity related stresses, particularly in coastal area are more pronounced and more damaging to crop production. The productivity of these soils can be restored by management and reclamation using different available technologies. Providing of adequate drainage, leaching out of soluble salts below root zone, cultivation of salt tolerant varieties/ halophytic plants, bio-saline agriculture, plantation of bio-shield including mangroves in coastal area, etc. have to be ensured for enhancing the productivity of these soils.Not Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableSalinity in coastal soils, unlike that in inland soils is caused during the process of their formation under marine influence and subsequently due to periodical influence of saline water either through inundation or capillary rise from shallow underground water or saline water irrigation. Coastal saline soils are having dominant salts of sodium chloride and sodium sulphate with abundance of soluble cations with dominance of Na followed by Mg, Ca and K and chloride as the predominant anion followed by sulphate. The coastal land needs protection against tidal inundation through protective embankment like bio-shield for control of sea ingress, soil erosion and salinity. Monsoonal rainfall intensity has increased during later period of Monsoon in the Western Coastal region. Unsuitable climatic conditions, soil and water degradation, marine influence in the coastal areas and secondary salinization in irrigation command areas minimized the land suitable for arable farming. Technological knowledge generated till date has helped in taming the problem in large tracts of land in different countries to restore their full productive potential. However, new challenges are set to be faced either due to changing climate or land use anomalies, leading to exponential increase in the area under salinity. With the new challenges cropping up, soil salinity related stresses, particularly in coastal area can be more pronounced and more damaging to crop production. The productivity of these soils can be restored by management and reclamation using different available technologies. Providing adequate drainage, leaching out soluble salts below root zone, cultivation of salt-tolerant varieties (halophytic plants), bio-saline agriculture, and plantation of bioshield including mangroves in coastal area have to be ensured for enhancing the productivity of these soils. For management and enhancing the productivity in coastal black soils of Gujarat, different interventions have been evolved. Coastal ecosystems being rich in a wide variety of natural resources offer large scope to develop alternate and sustainable farming packages.Not Availabl

Not Available

Not AvailableSalinity has been a major factor constraining agriculture in Gujarat. Use of salt tolerant varieties is considered as one of economic and ecological approach to overcome this. Attempt was made to demonstrate potential of salt tolerant wheat varieties (KRL 210 and KRL 19) in salt affected Vertisols of Bara tract area of Gujarat. Study was conducted with 53 farmers from Bharuch district of Gujarat. Data were collected using personal interview of the farmers using a well structured interview schedule. Study found that in economic benefits, all farmers agreed that cultivation of salt tolerant varieties in salt affected areas helped in increasing the income of the farmers. In terms of social benefits, about 76 per cent farmers agreed that cultivation of salt tolerant varieties in saline areas helped in upliftment of small and marginal farmers and achieving food security of the household. In terms of environmental benefits, 96 per cent farmers agreed that saline land and moderate saline ground water could be effectively used for cultivation of salt tolerant varieties. For agronomic practices majority of farmers agreed that salt tolerant varieties had more number of tillers (96%) and less lodging and shattering tendency (92%). Under quality of output, all farmers agreed that eating quality of salt tolerant wheat varieties was good. Thus farmers ’response to salt tolerant wheat varieties was good, which helped them in increasing their income; bringing their saline land under cultivation, securing household food security. However, there is need to create awareness among farmers in salt affected areas of Gujarat about presence and potential of such varieties which would help in increasing productivity and prosperity of these farmers.Not Availabl