Anil R. Chinchmalatpure

Growth and Yield of Salvadora persica, A Facultative Halophyte Grown on Saline Black Soil (Vertic Haplustept)

Salt-affected black soils (Vertic Haplustepts), due to high salinity and nutrient deficiency associated with erratic rainfall pattern pose management problems for sustainable agriculture. Cultivation of economic halophytes is considered as an alternative management strategy for bringing such problematic soils under production. Salvadora persica, a facultative halophyte and a good source of seed oil has been found to be highly salt tolerant. Attempts have been made to develop the agromanagement strategies for its domestication. The growth, biomass and seed and oil yield of S. persica grown on highly saline black soil with salinity ranging from 25 to 65 dS m−1 and cost/benefit ratio are reported in this article along with its cultivation and other uses. The seed yield declined by 40–47% at high salinity of 55–65 dS m−1 when compared to that of 25–35 dS m−1. The seed oil content, however, did not vary much under these salinity classes. The study indicated Salvadora persica, a medium-sized tree can be cultivated for restoration of highly saline black soils which are not suitable for conventional arable farming.

Effects of municipal solid waste compost, rice-straw compost and mineral fertilisers on biological and chemical properties of a saline soil and yields in a mustard–pearl millet cropping system

We investigated the effects of organic amendments, municipal solid waste compost (MSWC) and rice-straw compost (RSC) with and without mineral fertilisers on biological and chemical properties of a saline soil. Field experiments were conducted for two consecutive years during 2012–14. In the first year, application of 8tha–1 of MSWC+50% of the recommended dose of fertilisers (RDF) resulted in higher microbial biomass carbon (MBC), enzyme activities, soil organic carbon (SOC), available nitrogen (N), phosphorus (P) and potassium (K) than 7tha–1 of RSC+50% RDF, after mustard (Brassica juncea) and pearl millet (Pennisetum glaucum) harvests. Combined use of 8tha–1 of MSWC+50% RDF resulted in 47% and 54% more MBC than the unfertilised control after mustard and pearl millet harvests, respectively. Dehydrogenase activity was significantly higher with 100% RDF than the control after 2 years of the cropping cycle. Among organic amendments, MSWC was superior to RSC in terms of MBC, and activities of dehydrogenase, alkaline phosphatase and urease. SOC was significantly increased under MSWC+50% RDF compared with 100% RDF alone. Significant build-up of soil fertility in terms of available N, P and K was observed with RSC+50% RDF compared with the control. During the second year of the cropping system, soil treated with RSC+50% RDF had 14%, 17% and 9% higher N, P and K than soil treated with 100% RDF, after pearl millet harvest. The magnitude of change in soil electrical conductivity and pH was low during 2012–13; however, soil salinity decreased by 55% and 48% with MSWC+50% RDF and RSC+50% RDF, respectively, relative to the control at 120 days of pearl millet growth in 2013–14. Application of MSWC +50% RDF produced 2.5 and 2.70tha–1 of mustard and pearl millet, and increased grain yield by 19% and 15%, respectively, compared with 100% RDF. Integrated use organic amendments and mineral fertiliser is recommended for promoting biological and chemical properties of saline soil in a mustard–pearl millet cropping system.

Land Evaluation of Dotikol Micro-Watershed in North-Eastern Transition Zone of Karnataka

A study was undertaken to evaluate nine soil series belonging to Dotikol micro-watershed in Kalaburagi district in North-Eastern Transition Zone of Karnataka for sustainable land use planning. The soil series were Chimmanboda (CMB), Chimmanchod (CMH), Chincholi (CNL), Dotikol (DTK), Hasiragundgi (HGD), Karakmukali (KKK), Narnal (NNL), Rummanguda (RMG) and Ranapur (RNP) mapped into twenty mapping units and soil map was generated using GIS technique. The soils were evaluated for land capability classification, and categorized as land capability classes III, IV and VI based on limitations of erosion, drainage and physicochemical properties. Soil-site suitability assessment reveals that lowland and midland are moderately suitable (S2) for cultivation of field crops like sorghum, red gram, green gram, bengal gram, black gram and soybean with moderate limitations of drainage and fertility, while upland area is marginally suitable (S3) for cultivation of these crops. The uplands are not suitable (N) for horticultural crops like mango, guava, sapota, custard apple and jamun, because of severe limitation of depth. Whereas, lowland and midland, with moderate limitations of rooting depth and texture are moderately suitable (S2) for these crops.

Use of Saline Water/Industrial Effluents in Diverse Crop Interventions in Vertisols

With the rapid development of the global economy, the expansion of urban areas, and the increase of annual industrial and municipal water consumption, the imbalance between supply and demand of water resources is becoming a more and more serious problem around the world. Soil and irrigation water salinity are the two major constraints in agricultural production in arid and semiarid regions, and the impact of these two is more pronounced in the Vertisol regions. Vertisols, because of their physical constraints such as low hydraulic conductivity, poor infiltration rates, very high swelling clay minerals, and narrow workable moisture range, pose serious constraints in crop production even at low salinity. The above constraints also hinder drainage measures to a large extent, and thus tackling salinity problems in Vertisols solely lies on location-specific soil, crop, and water management strategies. These soils with subsurface salinity and saline groundwater need crop-based irrigation strategies and conjunctive use of saline groundwater along with soil management approaches. While highly saline soils can be brought under cultivation of economic halophytes such as trees like Salvadora persica and forages, conjunctive use of saline groundwater with surface water forms an ideal approach for oilseed crops, fiber crops like cotton, and seed spices. An alternative approach, i.e., the use of the industrial (treated) effluent from fertilizer and petrochemical units in diverse crop interventions like forages, oilseed crops, flowering plants, and biofuel species, is also feasible and also highlighted. These approaches clearly suggest that the use of saline groundwater and the treated effluent while enhancing the crop productivity also results in significant water savings.

Geomorphic Site Analysis to Study Soils Developed on a Toposequence of Schist Landform in Yadgir District of Karnataka

Three representative diversified pedons namely red, brown and black from the geomorphic units upper, middle and lower sectors, respectively in a toposequence on schist landscape were studied for their morphological, physical and chemical properties to understand the genesis and to classify as per USDA Soil Taxonomy. Red pedon was well drained as it recorded the highest (3) moist chroma and the drainage got poor down the slope in brown and black pedons where the moist chroma was 2 and 1, respectively. Dominant soil colour hue was 5YR in red pedon and 7.5 YR and 10 YR in brown and black pedons, respectively. Soil texture got finer down the slope and it was gravelly clay loam in red pedon and clay in both brown and black pedons. Clay skins, pressure faces and slickensides were observed in red, brown and black pedons, respectively. Chemical composition of fine sand fraction of pedons was almost same in all the pedons and CEC/clay, Feo/Fed and SiO2/Fe2O3 ratios showed increasing trend down the slope. The pedogenic processes associated with the upper sector member red pedon were leaching, decalcification, tendency of desilicification, laterization and kaolinization under well drained condition whereas, the middle and lower sector members brown and black pedons were formed by the pedogenic processes like calcification and silicification under poor drainage condition. Thus, a difference in drainage conditioned by topography is the important pedogenic factor in the genesis of diversified soils in a toposequence. At sub group level red, brown and black pedons were classified as Typic Haplustalfs, Vertic Haplustepts and Leptic Haplusterts, respectively.

Morphophysiological Traits Imparting Salinity Tolerance in Maize (Zea mays L.) Hybrids under Saline Water Irrigation in Vertisols

ABSTRACT Maize is categorized as a salt-sensitive crop and identification of fairly salt-tolerant lines is of paramount importance for increasing its production on saline soils. Experiments were conducted in randomized block design with three replications to identify maize accessions showing response to saline water irrigation, traits imparting tolerance, and their effect on yield attributes of maize. Significant variation was present among genotypes for specific leaf area (SLA), potassium (K) content, cob characteristics, yield, biomass, and harvest index. High amount of heritability with large genetic advance indicated the presence of additive gene action for traits like leaf water potential and leaf dry weight. Association analysis revealed high correlation between key traits and direct as well as positive effect of these traits on yield. Principal component analysis resolved three principal components, and high leaf area and water potential were conferring salt tolerance and thus higher yield.