G. Gururaja Rao

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.

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.

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.