Combined Application of Potassium and Zinc Improves Water Relations,Stay Green,Irrigation Water Use Efficiency,and Grain Quality of Maize under Drought Stress

Abstract

Maize (Zea mays L.) plays an important role in the global food security, but its production is threatened by climate change, especially drought stress. Potassium (K) and zinc (Zn) are considered useful to mitigate the negative consequences of drought stress in plants. Therefore, the objective of this two-year study was to identify the best combination of K and Zn application to improve the water relations, photosynthetic pigments, yield, irrigation water use efficiency (IWUE) and grain quality of maize sown under mild and severe drought stress conditions. The consisted of three drought stress levels viz. 1) well-watered as control (WW), 2) mild drought (MD) with 25?mm of potential soil moisture deficit (PSMD), 3) severe drought (SD) with 50?mm of PSMD and six K-Zn treatments: i.e. 125, 100 and 150?kg ha^?1 K with 0 and 12?kg ha^?1 Zn. The results indicated that K-Zn application improved the water relations and chlorophyll contents, biological yield and grain quality, irrespective of water stress treatment. The combined application of K-Zn under mild drought stress produced statistically same biological yield and grain quality as under well-irrigated without K-Zn fertilization and also produced compratively higher IWUE, biological yield and grain quality under sverer drought stress. Hence, the application of K at 150?kg ha^?1 in combination with Zn at 12?kg ha^?1 might be useful to improve the maize production and grain quality under drought stress. As IWUE was low in WW conditions, therefore, irrigation scheduling must be re-evaluated for optimum water use efficiency.     

In situ immobilization of Cr and its availability to maize plants in tannery waste–contaminated soil: effects of biochar feedstock and pyrolysis temperature

Journal of Soils and Sediments - Tannery waste–contaminated soil has a high amount of several toxic chemicals and heavy metals including chromium (Cr), which makes it unsuitable for...     

Rhizobia in tropical legumes—VII. Effectiveness of different isolates on Psophocarpus tetragonolobus (L.) DC

Rhizobia isolated from fourteen different genera of legumes were tested for their N-fixing effectiveness with Psophocarpus tetragonolobus in standard Leonard jar trials. Isolates from all plants except Pithecellobium jiringa were able to form nodules with P. tetragonolobus although a wide range of effectiveness amongst the different rhizobia was demonstrated. Thus P. tetragonolobus may be considered promiscuous with respect to its rhizobial requirements. Based on this experiment, a group of rhizobia comprising three elite strains (RRIM 56 from P. tetragonolobus, UMKL 36 from Lablab purpureus and CB 756 from Macrotyloma africanum, a moderately effective strain (NGR 258 from P. tetragonolobus), and two strains of low effectivity (RRIM 968 from Centrosema pubescens and UMKL 12 from Phaselus angularis) were selected for further study. When these were used to inoculate P. tetragonolubus growing in soil taken from virgin jungle (less than 1.54 rhizobia g^?1 soil); RRIM 56 and UMKL 36 again performed well, but NGR 258 outperformed CB 756.     

Functional Properties of Rice Bran Protein Isolate at Different pH Levels

The functional properties of proteins from Tarom and Shiroodi cultivars were determined and compared with technological aspects of food and nutraceutical applications. Shiroodi has higher protein content than Tarom, and the yields of protein obtained were 72.88 and 66.36%, respectively. Nitrogen solubilities of rice bran protein of Tarom were more than Shiroodi at all pH levels. In addition, higher solubility was found in acidic or alkaline conditions. Although the rice bran proteins had lower emulsifying properties than bovine serum albumin, they had similar foaming properties in comparison with egg white. Tarom isolates had a significantly higher solubility, emulsifying property, and foaming stability and greater surface properties than Shiroodi isolates. The results showed the surface hydrophobicities of rice bran protein were greater than casein and ovalbumin and lower than other proteins such as bovine serum albumin. Water and oil absorption capacities were 1.03 and 1.66 for Tarom and 87.3 and 75.3 for Shiroodi, respectively. The bulk densities of Tarom and Shiroodi were also 0.55 and 0.53 g/mL, which make them suitable for weaning food and other industrial applications. As a result, these rice bran proteins showed higher hydrophobicity than that of other rice bran protein varieties as well as more functionality. Thus, they have good potential in the food and pharmaceutical industries.     

Forest conversion adversely affects native Macrobrachium shrimp assemblages in tropical Malaysian streams

1. Commodity-driven forest conversion represents one of the most severe threats to freshwater biodiversity in Southeast Asia, notably causing population declines and the extinction of freshwater fish species.
2. Although a variety of freshwater taxa are likely to be adversely affected by forest conversion, little is known about the impact on ecologically and economically important invertebrates such as decapod crustaceans.
3. This study evaluated the impact of forest conversion and land-use change on freshwater Macrobrachium shrimp species, using species richness, abundance, and environmental data collected from 20 streams across southern Peninsular Malaysia. Streams were located in three types of landscape: forest; oil palm plantation; and mixed land use, comprising young secondary forest, small-scale plantations, patches of open and sparsely vegetated areas, and agricultural fields and clearings.
4. Generalized linear models showed that even incomplete change from forest habitats to mixed land use and oil palm plantation resulted in significantly lower Macrobrachium native species richness and higher non-native species abundance. Native species richness was positively correlated with canopy cover, leaf litter, substrate size, and dissolved oxygen, and was negatively correlated with water temperature and conductivity. Native species richness was also negatively correlated with non-native species abundance, with non-native species abundance increasing along the human disturbance gradient.
5. These results highlight the need for riparian habitat protection to conserve native Macrobrachium and limit the spread of non-native species. A management priority should be to maintain or restore optimum instream habitat conditions for shrimps, which would also benefit fish and other benthic macroinvertebrates. Suitable riparian management requires substantial support and funding from multiple stakeholders, but it can be aligned with other catchment-based strategies to optimize the use of limited resources available for freshwater biodiversity conservation.

     

Recent advances in the chemistry of nitrogen,phosphorus and potassium as fertilizers in soil: A review

The advent of civilization has made humans dependent on plants for food and medicine, leading to the intensification of agricultural production. The intense cultivation of crops has resulted in the depletion of available nutrients from soil, thereby demanding the application of excess nutrients to soil to improve yield. Thus, mineral fertilizer discovery and application have, in many ways, contributed greatly to meeting global food demands. However, aside from the positive effects of mineral fer...