Ayaz Mehmood

Relationship of Phosphorus Uptake with Its Fractions in Different Soil Parent Materials

The objectives were to determine inorganic P fractions in selected parent material soils and to develop a relationship of various P fractions with P uptake by Zea mays . Experimental study was conducted at Soil Chemistry Laboratory, Department of Soil Science and Soil and Water Conservation, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan, during February, 2013 to January, 2014. Triplicate soils were selected at three different level of development in each of loess, alluvium, shale residuum, and sandstone residuum, and surface and subsurface samples were taken. Samples were analyzed for pH, soil test P, total P, CaCO 3, dissolved and total organic carbon, dithionite extractable and amorphous iron. Soil P was fractioned into Ca 2-P, Ca 8-P, P adsorbed by Fe and Al, P occluded in iron oxides bodies, and apatite-P. Apatite-P was 33-71 %, and secondary phosphates i.e. occluded P, iron oxides surface adsorbed P and aluminum oxides surfaces adsorbed P ranged between 0.80 – 4.0 %, 2.65 – 14 % and 1.20 – 5.0 % of total P, respectively. Phosphorus uptake also differed significantly with soil parent material. The bioavailability of soil P fractions follow the order Ca 2-P > Org-P > Al-P > Fe-P > Ca 8-P > Occluded P > apatite-P. Dicalcium phosphates, iron adsorbed P, aluminum oxides adsorbed P and organic P control P bioavailability in Zea mays . Olsen P and occluded P gave better prediction for P uptake rather than Olsen P alone. This study will help to improve P fertilizer management and ultimately result in increase crop production. Original Research Article

Iron Oxides Minerals in Soils Derived from Different Parent Materials

The knowledge on soil iron oxides morphology and crystallization is important for the management of nutrients especially phosphorus. The objectives of the study were to determine the iron oxides minerals in Pothwar uplands. In the study one soil from each parent material (loess, alluvium, sandstone and shale) was selected. Selected clay samples suspensions were observed under transmission electron microscope. Ferrihydrite was common iron oxide mineral observed in all selected parent material soils at different level of crystallinity. Ferrihydrite was observed in scattered granules and also as aggregates or clusters. Crystalline iron oxides hematite and lepidocrocite was observed only in shale derived Murree soil. Mica and Rutile were the inorganic crystalline material on which masses of ferrihydrite was scattered. Energy dispersive spectra of scattered ferrihydrite masses show it has more phosphorus than lepidocrocite and hematite. The study concludes that ferrihydrite was the major iron oxides mineral in all selected parent material soils while shale derived soil also had lithogenic hematite and lepidocrocite. Short Research Article Mehmood et al.; IJPSS, 5(2): 110-116, 2015; Article no.IJPSS.2015.065 111

Water stress effects on biochemical traits and antioxidant activities of wheat (Triticum aestivum L.) under In vitro conditions

ABSTRACT Water stress is one of the major environmental stresses that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water deficit, induced by PEG-6000 on wheat genotypes (GA-2002, Chakwal-97, Uqab-2000, Chakwal-50 and Wafaq-2001) grown in modified MS medium solution. Osmotic stress caused a more pronounced inhibition in leaf relative water content and leaf membrane stability more sensitive (index in Wafaq-2001 and Uqab-2000) genotypes compared with the tolerant (Chakwal-50, GA-2002 and Chakwal-97) genotypes. Upon dehydration, an incline in proline, total soluble sugar, total soluble protein, superoxide dismutase, peroxidase, catalase and malondialdehyde activity content were evident in all genotypes, especially at osmotic stress of −8 bars. The observed data showed that status of biochemical attributes and antioxidant enzymes could provide a meaningful tool for depicting drought tolerance of wheat genotypes. The present study shows that genotypic differences in drought tolerance could be likely attributed to the ability of wheat plants to induce antioxidant defense under drought conditions. In order to develop genotypes with stable, higher yields in dry farming conditions, it is necessary to characterise genetic resources based on drought adaptation, determine suitable genotypes, and then use them in breeding programmes.

Sunflower (Helianthus annuus) Hybrids Evaluation for Oil Quality and Yield Attributes under Spring Planting Conditions of Haripur, Pakistan

Field experiment was conducted at the University of Haripur, Pakistan, to explore the role of photothermal units on oil contents, fatty acids profile, yield and yield traits of four sunflower hybrids viz SMH-0917, NK-S-278, SMH-0907 and Hysun33. These sunflower hybrids were selected because the farmers of that area are mostly relying on these hybrids for sunflower production. Sunflower hybrids were sown in spring and arranged under Randomized Complete Block Design with 3 replications under field conditions. Significant variation (p ≤ 0.05%) was found among the sunflower hybrids for photothermal unit requirements for flower completion and physiological maturity. Highest photothermal unit accumulation was found in Hysun33 followed by SMH-0917 and SMH-0907. Highest seed oil content and oil composition (linoleic and oleic acid were most abundant, whereas palmitic acid was least) was recorded in Hysun-33, SMH-0917 and SMH-0907. Overall Hysun-33, SMH-0917 and SMH-0907 performed better for plant height, head diameter, number of achenes per head and achene yield under field conditions. It was also observed that temperature and moisture availability positively influenced the oil quality of sunflower hybrids under spring planting conditions. The significant amount of variation within the sunflower population for photothermal unit accumulation, oil content, oil quality, and yield traits under these uniform field conditions reveals potential genetic variation that could be useful in breeding early maturing and high yielding local sunflower hybrids.

Arsenate and arsenite adsorption in relation with chemical properties of alluvial and loess soils

Arsenic is one of the most toxic elements in the soil environment. Understanding of the arsenic adsorption chemistry is essential for evolving the extent of soil and groundwater contaminations. This research was conducted to determine the variation in adsorption behaviour of arsenite and arsenate with depth in different lithology soils. We sampled two parent materials at genetic horizons, and within a parent material, we selected two soils. Besides basic soil characterizations, a laboratory batch experiments were carried out to study the adsorption of arsenate and arsenite. Freundlich adsorption approaches were employed to investigate the adsorption of arsenate and arsenite in the soils. Freundlich isotherms fit arsenate and arsenite sorption data well with r 2 values of 0.88–0.98 in most soils. Arsenate and arsenite adsorption varied with the soil properties, especially in clay composition and in the oxides of iron and aluxadminum. Arsenic adsorption parameters also varied with depth in parent matxaderials, and loess derived soils had greater adsorption capacity as compared to alluvial soils in most of the adsorption parameters. This research concludes that the loess soils had higher arsenic adsorption capacity than the alluvial soils.

Changes in soil phosphorus fractions across a toposequence in the estuary plains of Pakistan

ABSTRACT Understanding the regional dynamics of soil phosphorus (P) chemistry is essential for developing the best fertilizer management practices aimed at enhancing P use efficiency in cropping systems. The soil content of apatite, an important P-containing lithogenic mineral, can be influenced by its position in the local relief of a landscape. The objective of this study was to determine quantitative distribution of various P-forms in estuary plains of southern Pakistan in relation to soil genesis. Soils at different positions within the estuary plain were sampled at various genetic horizons. Apatite-P was the most abundant inorganic P constituent (380-590 mg kg−1) in all cases, followed in decreasing abundance by iron oxides surfaces adsorbed phosphorus (Fe-P), octacalcium phosphates (Ca8-P), aluminum oxides with surface bound P (Al-P) and the least abundant was the phosphorus occluded in iron oxides mineral (Occl-P). The abundance of apatite-P and these other forms of secondary phosphate varied for the soils at different relief positions in these estuary plain landscapes.

Photo-induced changes in quality attributes of potato tubers during storage

The retail display of potato tubers is carried out in supermarkets under additional light sources to impart aesthetic value and consumer’s attention, however, is associated with potato greening and associated disorders. The objective of this study was to identify a most appropriate light source for potato variety ’Lady Rosetta‘ along with photo-induced changes in different quality parameters. Potato tubers were placed for 27 days at ambient storage (25 ± 2 °C) under different light sources i.e. blue, fluorescent, green, mercury and red along with dark storage, which also served as normal control. In general, quality parameters, such as sugars, chlorophyll, total glycoalkaloids, increase while attributes, such as starch and ascorbic acid decrease during the storage period. The initial increase followed by final decline has been observed in parameters, such as total phenolic contents and radical scavenging activity. The results showed maximum retention of different quality attributes in dark potato storage. Amongst different light sources mercury and green light retained appreciable retention of different quality parameters with non-significant difference estimated between them in most of the studied parameters. Storage of potato under fluorescent, red and blue light proved to be precarious due to skin discoloration. Overall results revealed tuber sensitivity to different colored light along with their potential storage stability in the retail markets.

Ecosystem carbon sustainability under different C-equivalence inputs and outputs in dry land

The efficient use of carbon is the principle goal of achieving the agrixadcultural and environmental sustainability. Thus, study was aimed to compare the C-equivalence (C eq ) of inputs and outputs and the C index of sustainability ( Is ). Five cropping sequences were; fallow–wheat (FW, Triticum aestivum ) (control), mungbean ( Vigna radiata )–wheat (MW), sorghum ( Sorghum bicolor )–wheat (SW) green manure–wheat (GW) and mungbean-chickpea ( Cicera rietinum , MC). Tillage systems included moldboard 14 plough (MP), deep tillage (DT) and minimum tillage (MT). The primary data collected were crop yield and the above-ground biomass. Fuel utilization in MP was 15.2 kg C eq ha -1 with two ploughing per year, C input was 30.4 kg C eq ha -1 . In DT it was 11.6 kg C eq ha -1 . Herbicide used based input was 27.3 kg C eq ha -1 . The C eq of outputs differed among tillage treatments, and were: 135, 112 and 80.47 kg C eq ha -1 for MP, DT and MT, respectively. On the average of two years, the highest grain C eq was measured under MP and under SW in winter (1040 kg C eq ha -1 ). The maximum C eq biomass was estimated in winter with MC (2867 kg C eq ha -1 ). However, the highest root C eq under MT was calculated in winter with MW (9500 kg C eq ha -1 ). Under MT, the maximum Iswas obtained with MC for both years in summer (77 and 130). In winter of the second year, the highest Is was estimated for FW (82). These results showed that the efficient use of fertilizers, herbicides and farm machinery in the field under MT, with legume based cropxadping system, could be the best option to enhance the carbon Is in dry lands.

Transition in quality attributes of potato under different packaging systems during storage

The suitability of different packaging materials i.e. jute, nylon, polypropylene, cotton, low density polyethylene, medium density polyethylene and high density polyethylene were studied along with the control on the premium potato variety “Lady Rosetta”. After the harvest potato tubers were washed, sorted, graded, cured and subsequently stored in different packaging materials at ambient temperature (25±2 o C). Transition in quality attributes of potato tubers under different packaging materials were studied on the basis of their physico-chemical and functional parameters. Overall results revealed that packaging materials had significant (p ≤ 0.05) effect on most of the quality attributes studied. In general weight loss, glucose, glycoalkaloids, polyphenol oxidase, peroxidase, increased while ascorbic acid contents decreased with the increase of storage time. Total phenolic contents and radical scavenging activity showed a sort of parabolic trend during the storage period. Amongst different packaging employed potato stored in polypropylene and low density polyethylene packaging presented best overall retention of vital quality attributes during 63 days storage however, tensile strength of polypropylene packaging made it advantageous for prolonged potato storage coupled with easy transit operations during marketing.