Carbon,nitrogen, and phosphorus stoichiometry mediate sensitivity of carbon stabilization mechanisms along with surface layers of a Mollisol after long-term fertilization in Northeast China

Journal of Soils and Sediments - Soil organic carbon (SOC) is an important parameter determining soil fertility and sustaining soil health. How C, N, and P contents and their stoichiometric ratios...     

Salinity and drought affect yield response of bell pepper similarly

Abstract

There is a growing realization that an increasing number of countries are approaching full utilization of their conventional water resources and that the quantity of good-quality water supplies available to agriculture is diminishing. Effects of irrigation regime and irrigation water salinity on bell pepper including yield, fruit number and quality, vegetative and root growth, evapotranspiration and water use efficiency were investigated in this study by conducting two different experiments. Six different salinity levels of irrigation water and four different irrigation regimes were used as treatments. Considering the results from irrigation water salinity experiment, it can be concluded that as soil salinity increases, water consumption, water use efficiency, yield and other vegetative growth parameters of bell pepper were decreased. A polynomial relationship between soil salinity and water consumption was observed. It was found that bell pepper is moderately sensitive to salinity with a 1.2 dS m^?1 threshold and a 10.9% slope value. In the irrigation regime experiment, limited irrigation caused decreases in water consumption, yield and vegetative growth of bell pepper. Yield response factors were close in the cases of irrigation regime (1.50) and irrigation water salinity (1.40). Total soluble solids of bell pepper were increased due to both irrigation water salinity and water application rate but not dry matter ratio. Considerable water consumption decreases because of salinity were determined. Therefore, the effect of irrigation water salinity should be considered in irrigation management to prevent excess saline water application and to protect the environment.     

Ecogeographic survey and gap analysis of Lathyrus L. species

The genetic diversity of the genus Lathyrus is of significant importance, particularly for its role in sustaining the livelihoods of local communities living under very harsh conditions and its potential to adapt to climate change. Grasspea (L. sativus) is the most widely used species and to a lesser extent L. cicera and L. ochrus, each is used for animal feed in many parts of the world and food in poorer regions, but human over-consumption of the seeds can lead to lathyrism, a disease caused by neurotoxins. This study has added substantial information and accuracy to the existing global Lathyrus database by combining diverse datasets and by adding information of major herbaria from Europe. This global Lathyrus database, available at ICARDA, was used to conduct gap analysis to guide future collecting missions and in situ conservation efforts for highest priority species originating from the Mediterranean Basin, and Caucasus, Central and West Asia region. The results showed the highest concentration of Lathyrus priority species are found in the Fertile Crescent countries, France, Italy and Greece. The area either side of the Lebanese/Syrian border near Tel Kalakh, Syria was identified as the hotspot and the overall priority location for establishing the first in situ genetic reserve. The gap analysis for ex situ conservation shows that only six species (representing 16.6 %) of the 36 priority species are adequately sampled. Only L. cicera has already been well sampled among the closely related species to cultivated species L. sativus, indicating further collecting of L. amphicarpos, L. belinensis, L. chrysanthus, L. hirticarpus, L. hirsutus and L. marmoratus is required. In addition, six secondary priority Lathyrus species have no ex situ collections (L. lentiformis, L. lycicus, L. phaselitanus, L. trachycarpus, L. tremolsianus and L. undulatus) and also require targeted collecting.     

Growth,transpiration, root‐born cytokinins and gibberellins,and nutrient compositional changes in sesame exposed to low root‐zone temperature under different ratios of nitrate: Ammonium supply

The growth of sesame (Sesamum indicum L.) was studied at three root temperature regimes (25/25, 20/10 and 15/15°C day/night) factorially combined with three NO₃ ^‐: NH₄ ⁺ ratios (mM ratios, 10:0, 8:2, or 6:4), as a source of nitrogen (N), in the irrigation solution. The air temperature was kept constant at 30°C. Transpiration, nutrient composition, and level of root‐born cytokinins and gibberellins in the xylem exudate were monitored. The two low root temperature regimes, 15/15 and 20/10°C, restricted the growth of sesame, reduced transpiration and increased the accumulation of soluble carbohydrates in the shoot and in the roots compared to the 25/25°C regime. The NO₃:NH₄ ⁺ ratios had no effect on growth. Nutrient contents in the shoot at low root temperatures, particularly K⁺, NO₃ ^‐, and H₂PO₄ ^‐ were decreased markedly, but Na⁺ increased relative to it's content in the 25/25°C regime. Increasing NH₄ ⁺ proportion in the irrigation solution raised total N concentration in the plant tissues at all root temperatures. The amounts of cytokinins and gibberellins in the xylem exudate decreased at the low root temperature regimes relative to the 25/25°C regime. Low root temperature reduced xylem transport of nutrients and root born‐phytohormones, most probably because of reduced water flow through the plant relative to the 25/25°C regime.     

Interspecific Facilitative Root Interactions and Rhizosphere Effects on Phosphorus and Iron Nutrition Between Mixed Grown Chickpea and Barley

A glasshouse study was conducted to investigate the effects of interspecific complementary and competitive root interactions and rhizosphere effects on phosphorus (P) and iron (Fe) nutrition of mixed grown chickpea (Cicer arietinum L.) and barley (Hordeum vulgare L.). In order to provide more physiological evidence on the mechanisms of interspecific facilitation, we determined phosphatase activities in plant and rhizosphere, and root ferric reducing capacity (FR), Fe-solubilizing activity (Fe-SA) and rhizosphere pH. The results of the experiment revealed that biomass yield of barley was significantly increased by associated chickpea as compared to monocultured barley, while mixed cropping caused a slight decreases in the biomass yield of chickpea. The rhizosphere was strongly acidified under chickpea and chickpea/barley mixed cropping and this acidification, in turn, increased the available P, Fe(II) and DTPA-Fe concentrations in the rhizosphere. Fe-solubilizing activity (Fe-SA) and ferric reducing (FR) capacity of the roots were higher in both species grown in mixed culture relative to their monoculture which may improve Fe nutrition of both species. Leaf acid phosphatase (APase, EC 3.1.3.2) activity was higher in both plants under mixed cropping that may improve P nutrition of barley by chickpea.     

Phosphorous and Mung Bean Residue Incorporation Improve Soil Fertility and Crop Productivity in Sorghum and Mungbean-Lentil Cropping System

ABSTRACT

In sorghum and mungbean – lentil cropping system, field experiments were conducted for three successive years to assess the effect of mung bean residue incorporation on sorghum and succeeding lentil productivity along with different doses of phosphorus (P; 0, 30, 60 kg ha^{? 1}) applied to these crops. The level of soil fertility was also tested with or without incorporation of mung bean residue. The interaction of phosphorus to mungbean residue incorporation was thus studied in relation to improve crop productivity with balancing fertilizer requirements through an eco-friendly approach. Sorghum grain yield increased significantly when 60 kg P₂O₅ ha^{? 1} was applied and mungbean residue incorporated. The response was reduced to 30 kg P₂O₅ ha^{? 1} when mungbean residue was not incorporated. The succeeding lentil crop responded up to 60 kg P₂O₅ ha^{? 1} only when preceding sorghum crop received 0 or 30 kg P₂O₅ ha^{? 1}. Response to applied P₂O₅ to lentil reduced to 30 kg ha^{? 1} when preceding sorghum crop received 60 kg P₂O₅ ha^{? 1} and mungbean residue incorporated. Available soil nitrogen, phosphorus, and organic carbon content increased when mungbean residue was incorporated; however, available potassium (K) of the soil decreased from its initial value.     

Zinc bioavailability and nitrogen concentration in grains of wheat crop sprayed with zinc sulfate,ammonium sulfate,ammonium chloride,and urea

Abstract

It is still unclear if different sources of nitrogen (N) can variably influence grain accumulation of zinc (Zn), N, and phytate. We tested foliar treatments of 0 or 0.25% Zn as zinc sulfate in combination with 0 or 1% N as ammonium chloride, ammonium sulfate or urea sprayed on field-grown-wheat (Triticum aestivum L.) foliage at anthesis and 10 days later. Leaf burning caused by ammonium chloride significantly decreased grain yield. Grain N concentration was the highest in the urea +0.25% Zn treatment. Foliar N application influenced grain Zn concentration only if Zn was included in the spray. Grain phytate concentration was significantly decreased by both N and Zn sprays. Estimated Zn bioavailability in grains was the highest at 0.25% Zn and was not influenced by the N sources. Based on grain yield, grain N concentration, and Zn bioavailability in grains, foliar application of Zn?+?urea is an optimal strategy.     

Effect of seed and foliar application of nano-zinc oxide,zinc chelate,and zinc sulphate rates on yield and growth of pinto bean (Phaseolus vulgaris) cultivars

Nanofertilizers have received considerable attention due to their increased uptake by plants. Therefore, this study aimed to investigate the effect of zinc oxide (ZnO) nanoparticles and also different zinc (Zn) fertilizers (Zn sulfate, Zn chelate) on vegetative and yield traits of two pinto bean cultivars “KS21191” and “KS21193”. This experiment was a factorial based on completely randomized design with 24 treatments (three fertilizer applications and eight levels of Zn fertilizer). The results showed that twice foliar application compared to seed application and once foliar application improved growth and yield characteristics of both pinto bean cultivars. Also, compared to control treatment, zinc nanofertilizers improved vegetative characteristics (such as plant height, internode length, root and shoot dry, and fresh weight), yield (pods number and seed weight) and quality (zinc content in seed) of both pinto bean cultivars. Among the zinc fertilizer treatments, 0.10% and 0.15% of ZnO nanoparticles were as a superior treatment.     

Regression-based phosphorus recommendation model for Washington Navel

Abstract

Many methods have been proposed to recommend phosphorus fertilizer, but none of them can quantitatively determine the plant phosphorus required. In this method, which is called “Integrated Plant and Soil System” (IPSS), the required phosphorus of the plant is calculated quantitatively, based off of the correlation between soil phosphorus, soil properties, and plant organs phosphorus. For this purpose, 39 Orange orchards were chosen in Jahrom (Iran). In each orchard during two consecutive years, samples were taken from the plant organs and soil of the root zone and phosphorus was measured. A multivariable regression was established between variables that had a significant correlation with soil phosphorus. The result of IPSS was two regression models between soil and fruit phosphorus. A regression model for high yield orchards (Y2?=?–121.3799?+?0.1256308X2), and the other for orchards that have a phosphorus deficiency (Y1?=?–96.4673?+?0.120549X1). According to these regressions, calculating the amount of phosphorus required for orange trees is possible.     

Influence of additional amino acids in growth of different wheat (Triticum aestivum L) genotypes

Abstract

Wheat is the main source of carbohydrates and amino acids consumed in the world. Amino acids and other physiological characters were determined in six wheat genotypes viz. IBWSN-1010, IBWSN -1025, TD-1, ESW-9525, Khirman and Chakwal-86 for pot experiment, to evaluate the response of genotypes under water stress at Nuclear Institute of Agriculture (NIA), Tandojam, Sindh, Pakistan, during 2018. Eight different physiological indices (Proline content, glycine-betaine, total sugars, total chlorophyll, nitrate reductase activity (NRA), potassium (K⁺) content, osmotic potential (OP) and relative water content (RWC)) were determined. The variance of analysis shows two-way interaction one with water stress [Control (normal four irrigations) and the other with terminal drought (Soaking dose) having significance at p?≤?0.05. It was observed that, ESW9525, IBWSN-1010 and IBWSN-1025 exhibited the tolerance followed by, Khirman and Chakwal-86 by maintaining their OP and accumulation of higher proline and glycine-betaine content. Whereas, moderate total soluble sugars were found in these genotypes. However, NRA increased in IBWSN-1010 enhancing tolerance under water stress.