Ground-Water Quality in Islamkot and Mithi Talukas of District Tharparkar, Sindh, Pakistan

Surface water supplies are gradually becoming short in arid and semi-arid regions of the world. Thus, assessment of groundwater quality for crop use appears to be very essential for management and utilization of precious natural water resources. This study reports the water quality of 52 hand pumps and one tubewell located in the most remote areas of desert region, viz. Islamkot and Mithi talukas of district Tharparkar. The water samples were collected during April 2016 (just before the start of rainy season). The water samples were analyzed for EC (Electrical Conductivity), pH, CO32-, HCO3-, Cl-, Ca2+, Mg2+ and Na+ concentration. The SAR (Sodium Adsorption Ratio) and RSC (Residual Sodium Carbonates) were estimated using their respective formula. The categorization of water samples based on their soluble salt content clearly revealed that the water bodies of majority (65%) of areas were hazardous, while 25% areas were marginal. Thus, only 11% water samples of the area under study had useable irrigation water. Because of SAR and RSC the majority (89 and 77%, respectively) of water samples were found to be free from the sodicity hazard. The study concluded that salinity, and not sodicity was the major threat to the area under irrigation with these water bodies. It is, therefore, suggested that the salinity tolerant crops and their genotypes may be used in this area to sustain crop production

Chromium toxicity in plants: consequences on growth, chromosomal behavior and mineral nutrient status

Chromium (Cr) is a heavy metal of commercial importance; thus, significant amounts are released in wastewaters. The mobility and distribution of metals in the environment is related not only to their concentration but also to their availability in the environment. Most chromium (Cr) exists in oxidation states ranging from 0 to VI in soils but the most stable and common forms are Cr(0), Cr(III), and Cr(VI) species. Cr can have positive and negative effects on health, according to the dose, exposure time, and its oxidation state. Its behavior in soil, its soil-plant transfer and accumulation in different plant parts vary with its chemical form, plant type and soil physicochemical properties. Soil microbial community plays a key role in governing Cr speciation and behavior in soil. A number of factors have been identified to influence Cr toxicity on activated sludge, such as, pH, biomass concentration, presence of organic substances or other heavy metals, acclimation process, exposure time, etc. Inside plants, Cr provokes numerous deleterious effects to several physiological, morphological, and biochemical processes. Cr induces phytotoxicity by interfering plant growth, nutrient uptake and photosynthesis, inducing enhanced generation of reactive oxygen species, causing lipid peroxidation and altering the antioxidant activities. The present review describes the consequences of Cr toxicity on plants, including morphological, physiological and ultrastructural changes. This review also provides the basic concepts of Cr translocation and interaction with other essential macro-and microelements. Moreover, based on the available literature and current research scenario, this review suggests some possible management and remediation strategies to alleviate Cr toxicity and contamination in soil. It also provides valuable knowledge for further studies towards enhancement of soil phytoremediation and crops improvement. Therefore, there is a dire need to monitor biogeochemical behavior of Cr in soil-plant system

Synergistic use of nitrogen and zinc to bio-fortify zinc in wheat grains

Our daily diet is largely contributed by cereals, which have low genetic abilities to amass higher concentrations of micronutrients in their grains. Hence, wide spread deficiencies iron, zinc and other essential nutrients have prevailed. Present study focuses the bio-fortification of Zn in wheat grains, taking advantage of nutrient-nutrient synergy between Zn and N. Three wheat genotypes (NIA-Amber, BWQ-4 and SD-998) were tested in a field experiment following randomized complete block factorial design with three replicates. Urea fertilizer was applied at the rates of 120 (recommended), 150 and 180 kg N ha-1 in combination with three levels of Zn (0, 5 & 10 kg ha-1). Outcomes of the experiment revealed that NIA-Amber had the highest grain yield of 6.03 tons/ha against 150 kg N ha-1 and 10 kg Zn ha-1. Maximum Zn contents of 447.86, 429.56 and 395.56 g ha-1 were observed in BWQ-4, SD-998 and NIA-Amber at 180 kg N ha-1 in combination with 10 kg Zn ha-1. Maximum enhancement in protein contents was observed in BWQ-4 (743 kg ha-1) at 180 kg N ha-1and combined with 5 kg Zn ha-1. For NIA-Amber, 180 kg N ha-1 in combination of 10 kg Zn ha-1 proved the most suitable in terms of Zn concentration and other quality attributes. Nitrogen @ 180 kg N ha-1 with 5 kg Zn ha-1 depicted appreciable zinc and protein contents in grains of BWQ-4 and SD-998

Grain Phytic Acid Accumulation of Domestic and Exotic Rice Genotypes in Zinc-Deficient Soil

Micronutrient malnutrition in humans living in rice growing areas is increasing rapidly due to less absorption of mineral nutrients chelated by phytic acid (anti-nutrients) present in rice grains. A field study was conducted to evaluate the grain phytic acid and zinc (Zn) accumulation of 10 field grown rice (Oryza sativa L.) genotypes on a Zn deficient soil. Both the Zn- efficient (Shua-92, IR-9, Shandar, IR-36, and IR-6) and Zn-inefficient (Sarshar,. UPL-48, Khushboo-95 and RG-120) rice genotypes were included in the study. The two Zn treatments (0 and 15 kg ha-1) were arranged in a two factor randomized complete block design with three replications. Nitrogen (N) and phosphorus (P2O5) were applied at the rate of 120 and 80 kg ha-1. The rice genotypes IR-36, UPL-79, Shandar and Shua-92 were the most Zn accumulators whereas; Sarshar, IR-9 and Khushboo-95 the least accumulator in Zn deficiency. Zinc in-efficient genotype Sarshar was the highest Zn accumulator in response to Zn application. Phytic acid content of rice genotypes was significantly influenced (p < 0.05) by the application of Zn fertilizer. Phosphorus concentration in rice grains decreased with Zn application. Zinc in-efficient genotypes accumulated more phytic acid in their food reserves than Zn-efficient genotypes. Phytic acid: zinc ratio decreased significantly more in Zn-inefficient genotypes as compared to Zn efficient genotypes, with application of Zn fertilizer. Zinc efficient genotype Shua-92 accumulated low concentration of phytic acid. The rice genotypes Shua-92, IR-9, Shandar and IR-36 low accumulators of phytic acid performed successfully and contained higher concentrations of Zn than other genotypes

Enhancing phosphorus use efficiency in wheat grown on alkaline calcareous soils

Phosphorus (P) use efficiency is crucial for sustainable wheat production, particularly on alkaline calcareous soils. This study investigates the relative importance of two factors; P acquisition efficiency (PAE) and P utilization efficiency (PUtE), in determining P use efficiency (PUE) in wheat. A field trial with ten wheat genotypes was conducted under two P levels (no P application and P application at 110 kg P2O5 ha−1). Results revealed significant genetic variability in PUE, PAE, and PUtE among wheat genotypes under varying P availabilities. Genotypes MK-4 and MK-8 exhibited superior PUE, making them ideal candidates for soils with differing P levels. PAE played a more substantial role in influencing PUE, with PUtE contributing less to the variability. The findings underscore the importance of improving PAE, particularly for wheat genotypes grown in P-deficient conditions. Moreover, selecting genotypes with lower grain P concentration can enhance PUtE, contributing to improved PUE. These insights can improve breeding efforts and crop management practices to enhance P use efficiency in wheat, ultimately reducing production costs and fertilizer demand, especially in P-limited alkaline calcareous soils

Optimum wheat productivity under integrated plant nutrient management is associated with improved root system and high nutrient efficiency

Depleting soil fertility and low fertilizer efficiency in alkaline calcareous soils are serious issues worldwide creating an immediate threat to environment and food security. Integrated nutrient management (INM) can be a promising eco-friendly strategy for improving crop performance and resource efficiency to resolve these concerns. A field study was conducted to investigate the integrated effect of organic sources [farm yard manure (FYM) @ 10 tons ha-1 and press mud (PM) @ 5 tons ha-1] along with various NPK rates [100, 75, 50% recommended dose of fertilizer (RDF)] on root system, nutrient efficiency, and yield of wheat cultivar Kiran-95. Longest roots were measured in FYM + RDF50 while highest surface area and number of root tips were recorded in PM + RDF50 than RDF alone. However, maximum root volume and average root diameter was observed in PM + RDF100 and PM + RDF75, respectively compared with RDF only. PM + RDF100 considerably enhanced grain yield and related traits i.e., spike length, tillers count m-2 and 100-grain weight as compared to RDF only. Integration of PM and 100% RDF showed higher NPK uptake, than RDF alone. Recovery efficiency (RE) of NPK was calculated higher at lower fertilizer rates and vice versa. The sole application of RDF100 showed least RE of NPK whilst PM + RDF50 revealed higher RE of NPK. The results suggested that INM could be a sustainable approach to enhance wheat productivity and nutrient efficiency in alkaline calcareous soils. In addition, PM along with RDF100 NPK fertilizers proved superior in improving root traits and nutrient accumulation thereby increasing wheat grain yield

Interactive effect of phosphorus and boron on plant growth, nutrient accumulation and grain yield of wheat grown on calcareous soil

Most of the arable soils in Pakistan are deficient in plant available phosphorus (P) and boron (B) primarily due to alkaline and calcareous nature along with low organic matter. A combined deficiency of these nutrients may intensify the plant growth suppression by reducing their efficient utilization. A pot experiment was conducted to investigate the interactive effect of P and B on growth, nutrient accumulation and grain yield of wheat grown on calcareous soil. Wheat crop was grown at three P levels (45, 90 and 135 kg P ha-1) in combination with five B levels (0, 0.5, 1.0, 1.5 and 2.0 kg B ha-1) following completely randomized design. The results revealed that yield and yield related attributes increased linearly with the addition of B at each P level. Nonetheless, the significant interactive effect of both nutrients was most pronounced in the treatment having 90 kg P ha-1 and 1.5 kg B ha-1. Applied B rates resulted in relatively higher P concentration in grains and straw at P level of 90 kg ha-1 contrarily to 45 and 135 kg P ha-1. The B concentration in grains and straw increased with corresponding addition of B at each P level but at variable rate, with the maximum response at higher P level. Grain and straw yield illustrated positive correlation with total P uptake (R2 = 0.96 and 0.81) and total B uptake (R2 = 0.95 and 0.70) respectively. Likewise, positive correlation (R2 = 0.94) between total P uptake and total B uptake under combined application of P and B indicated their synergistic relationship. Overall, the treatment combination of 90 kg P ha-1 with 1.5 kg B ha-1 was found as the most suitable dose for better plant growth, nutrient accumulation and grain yield of wheat

Enhancing iron concentration in bread wheat through Fe-EDTA fortification

Iron (Fe) malnutrition in humans is a global concern which can be revised by improved Fe density in staple crops. A field experiment was performed to evaluate the effect of chelated iron on growth, yield and iron concentration in bread wheat (cv. Moomal) at Tando Jam Pakistan. The treatments included, Control (No Fe-EDTA), Soil supplement of Fe-EDTA (@ 2 kg Fe ha-1), Soil + foliar supplement of Fe-EDTA (@ 2 kg ha-1 and 0.2% Fe at booting, flowering, and milky stage), and Foliar supplement of Fe-EDTA (@ 0.2% Fe at booting, flowering and milky stages). The defined growth and yield traits of wheat were increased with Fe-EDTA applications over control treatment. Among different Fe-EDTA application methods, there was no significant difference for most of the growth and yield parameters (excluding spike length, number of spikelets spike-1, and 1000 grain weight). The amount of Fe in wheat grains was significantly higher in all Fe-EDTA treatments over control, with maximum value (86.54 ± 5.57 mg kg-1) in the treatment where Fe-EDTA was applied in soil + foliar. Similarly, a high Fe build up in surface soil was obtained with treatment of Fe-EDTA in soil + foliar. Overall, with various Fe-EDTA treatments, an increase of 21.2 to 29.1% in grain yield and 1.9 to 4.3 times in Fe concentration of wheat grains was achieved in current study. It is suggested that the Fe should be included in wheat production technology to attain better yield and Fe concentration in grains