Amelioration of alkaline phytotoxicity by lowering soil pH

2014 ◽  
Vol 65 (12) ◽  
pp. 1278 ◽  
Author(s):  
D. J. Brautigan ◽  
P. Rengasamy ◽  
D. J. Chittleborough

Highly alkaline soils (pH >9) may adversely affect agricultural crop productivity. At pH >9.2, aluminium (Al) phytotoxicity may further retard plant development. Most alkaline soils have little alkaline buffering capacity, making it feasible to use acid to lower soil pH to <9.2. Many methods of lowering soil pH have been trialled; however, little research has been done on their relative effectiveness and longevity. Methods trialled in this study as means of lowering soil pH were chemical additives (gypsum), organic additives (glucose, molasses, horse manure, green manure, humus) and leguminous plants. Gypsum was also used in conjunction with plants to determine any synergistic effects of combining treatments. All ameliorants trialled except humus and horse manure proved effective at lowering soil pH to <9.2. The reduction achieved with biological amendments was temporary, with pH returning to pre-amendment levels over the course of the study. Gypsum was most effective amendment for lowering soil pH and sustaining the lowered pH level. The use of plants to lower soil pH, in conjunction with gypsum to sustain the lowered pH, may be an effective and economic method of remediating Al phytotoxicity in alkaline soils.

2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Lucas Dantas Lopes ◽  
Jingjie Hao ◽  
Daniel P Schachtman

ABSTRACT Soil pH is a major factor shaping bulk soil microbial communities. However, it is unclear whether the belowground microbial habitats shaped by plants (e.g. rhizosphere and root endosphere) are also affected by soil pH. We investigated this question by comparing the microbial communities associated with plants growing in neutral and strongly alkaline soils in the Sandhills, which is the largest sand dune complex in the northern hemisphere. Bulk soil, rhizosphere and root endosphere DNA were extracted from multiple plant species and analyzed using 16S rRNA amplicon sequencing. Results showed that rhizosphere, root endosphere and bulk soil microbiomes were different in the contrasting soil pH ranges. The strongest impact of plant species on the belowground microbiomes was in alkaline soils, suggesting a greater selective effect under alkali stress. Evaluation of soil chemical components showed that in addition to soil pH, cation exchange capacity also had a strong impact on shaping bulk soil microbial communities. This study extends our knowledge regarding the importance of pH to microbial ecology showing that root endosphere and rhizosphere microbial communities were also influenced by this soil component, and highlights the important role that plants play particularly in shaping the belowground microbiomes in alkaline soils.


2021 ◽  
Vol 22 (6) ◽  
pp. 3082
Author(s):  
Celia Delgado ◽  
Freddy Mora-Poblete ◽  
Sunny Ahmar ◽  
Jen-Tsung Chen ◽  
Carlos R. Figueroa

Soil salinity is one of the most limiting stresses for crop productivity and quality worldwide. In this sense, jasmonates (JAs) have emerged as phytohormones that play essential roles in mediating plant response to abiotic stresses, including salt stress. Here, we reviewed the mechanisms underlying the activation and response of the JA-biosynthesis and JA-signaling pathways under saline conditions in Arabidopsis and several crops. In this sense, molecular components of JA-signaling such as MYC2 transcription factor and JASMONATE ZIM-DOMAIN (JAZ) repressors are key players for the JA-associated response. Moreover, we review the antagonist and synergistic effects between JA and other hormones such as abscisic acid (ABA). From an applied point of view, several reports have shown that exogenous JA applications increase the antioxidant response in plants to alleviate salt stress. Finally, we discuss the latest advances in genomic techniques for the improvement of crop tolerance to salt stress with a focus on jasmonates.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Adeel Khan ◽  
Munir Ahmad ◽  
Mukhtar Ahmed ◽  
M. Iftikhar Hussain

Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in the crop is a challenging task for crop scientists. Therefore, this review work was conducted with the aim of providing information on the wheat response in three research areas, i.e., physiology, breeding, and advances in genetics, which could assist the researchers in improving thermotolerance. The optimum temperature for wheat growth at the heading, anthesis, and grain filling duration is 16 ± 2.3 °C, 23 ± 1.75 °C, and 26 ± 1.53 °C, respectively. The high temperature adversely influences the crop phenology, growth, and development. The pre-anthesis high temperature retards the pollen viability, seed formation, and embryo development. The post-anthesis high temperature declines the starch granules accumulation, stem reserve carbohydrates, and translocation of photosynthates into grains. A high temperature above 40 °C inhibits the photosynthesis by damaging the photosystem-II, electron transport chain, and photosystem-I. Our review work highlighted that genotypes which can maintain a higher accumulation of proline, glycine betaine, expression of heat shock proteins, stay green and antioxidant enzymes activity viz., catalase, peroxidase, super oxide dismutase, and glutathione reductase can tolerate high temperature efficiently through sustaining cellular physiology. Similarly, the pre-anthesis acclimation with heat treatment, inorganic fertilizer such as nitrogen, potassium nitrate and potassium chloride, mulches with rice husk, early sowing, presoaking of a 6.6 mM solution of thiourea, foliar application of 50 ppm dithiothreitol, 10 mg per kg of silicon at heading and zinc ameliorate the crop against the high temperature. Finally, it has been suggested that modern genomics and omics techniques should be used to develop thermotolerance in wheat.


By continuous and rapid growth in industrialization as well as population, the agricultural lands are also becoming less and less continuously day by day which results in increase in the population of small land holders. In addition to this, because of continuous decreasing production the youth of the villages are also migrating in big cities for the employment, resulting decreasing manpower essential to perform various seedbed operations in the villages. Hence, it is the need of time for small farmers having small agricultural land and having less crop production to introduce the cost-effective farm mechanization so that they can improve production rate. Rotavator is the best option available to achieve this landmark as it is already proved that seedbed prepared by using rotavator gives highest benefit to cost ratio. For this experimental study the whole land of 9 acre area is divided into 18 plots of equal size in area. The combination of method of seedbed preparation and use of fertilizers were the preliminary criteria. The categories of fertilizer according to quantity are discussed earlier which are 50kg, 35kg and 65kg per acre respectively. The quantities of organic fertilizer used are 45kg and 60kg per acre of agricultural land for both seedbeds which are prepared manually and by using rotavator. The highest production of Pigeon Pea was obtained of 814kg was from the plot whose seedbed is prepared by using agricultural machine called rotavator and organic fertilizer; next highest production is obtained of 802 kg from the plot whose seedbed is prepared by using rotavator and the fertilizer used was chemical fertilizer. The minimum production of Pigeon Pea which is 690 kg was obtained in the plot whose seedbed was prepared manually and chemical fertilizer was used.


2015 ◽  
Vol 12 (16) ◽  
pp. 13215-13240 ◽  
Author(s):  
W. Luo ◽  
P. N. Nelson ◽  
M.-H. Li ◽  
J. Cai ◽  
Y. Zhang ◽  
...  

Abstract. Soil pH buffering capacity (pHBC) plays a crucial role in predicting acidification rates, yet its large-scale patterns and controls are poorly understood, especially for neutral-alkaline soils. Here, we evaluated the spatial patterns and drivers of pHBC along a 3600 km long transect (1900 km sub-transect with carbonate containing soils and 1700 km sub-transect with non-carbonate containing soils) across northern China. Soil pHBC was greater in the carbonate containing soils than in the non-carbonate containing soils. Acid addition decreased soil pH in the non-carbonate containing soils more markedly than in the carbonate containing soils. Within the carbonate soil sub-transect, soil pHBC was positively correlated with cation exchange capacity (CEC), carbonate content and exchangeable sodium (Na) concentration, but negatively correlated with initial pH and clay content, and not correlated with soil organic carbon (SOC) content. Within the non-carbonate sub-transect, soil pHBC was positively related to initial pH, clay content, CEC and exchangeable Na concentration, but not related to SOC content. Carbonate content was the primary determinant of pHBC in the carbonate containing soils and CEC was the main determinant of buffering capacity in the non-carbonate containing soils. Soil pHBC was positively related to aridity index and carbonate content across the carbonate containing soil sub-transect. Our results indicated that mechanisms controlling pHBC differ among neutral-alkaline soils of northern China, especially between carbonate and non-carbonate containing soils, leading to different rates, risks, and impacts of acidification. This understanding should be incorporated into the acidification risk assessment and landscape management in a changing world.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7949 ◽  
Author(s):  
Chao Yang ◽  
Jingjing Li ◽  
Yingjun Zhang

Background Soil aggregate-size classes, structural units of soil, are the important factors regulating soil organic carbon (SOC) turnover. However, the processes of litter C mineralization and storage in different aggregates-size classes are poorly understood, especially in the highly alkaline soils of north China. Here, we ask how four different aggregate sizes influence rates of C release (Cr) and SOC storage (Cs) in response to three types of plant litter added to an un-grazed natural grassland. Methods Highly alkaline soil samples were separated into four dry aggregate classes of different sizes (2–4, 1–2, 0.25–1, and <0.25 mm). Three types of dry dead plant litter (leaf, stem, and all standing dead aboveground litter) of Leymus chinensis were added to each of the four aggregate class samples. Litter mass loss rate, Cr, and Cs were measured periodically during the 56-day incubation. Results The results showed that the mass loss in 1–2 mm aggregates was significantly greater than that in other size classes of soil aggregates on both day 28 and day 56. Macro-aggregates (1–2 mm) had the highest Cr of all treatments, whereas 0.25–1 mm aggregates had the lowest. In addition, a significant negative relationship was found between Cs/Cr and soil pH. After incubation for 28 and 56 days, the Cs was also highest in the 1–2 mm aggregates, which implied that the macro-aggregates had not only a higher CO2 release capacity, but also a greater litter C storage capacity than the micro-aggregates in the highly alkaline soils of north China.


2020 ◽  
Author(s):  
Lisa Wingate ◽  
Clement Foucault ◽  
Nicolas Fanin ◽  
Joana Sauze ◽  
Pierre-Alain Maron ◽  
...  

&lt;p&gt;The stable oxygen isotope composition of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; and the mixing ratio of carbonyl sulphide (COS) are potential tracers of biospheric CO&lt;sub&gt;2&lt;/sub&gt; fluxes at large scales. However, the use of these tracers hinges on our ability to understand and better predict the activity of the enzyme carbonic anhydrase (CA) in different soil microbial groups, including phototrophs. Because different classes of the CA family (&amp;#945;, &amp;#946; and &amp;#947;) may have different affinities to CO&lt;sub&gt;2&lt;/sub&gt; and COS and their expression should also vary between different microbial groups, differences in the community structure could impact the &amp;#8216;community-integrated&amp;#8217; CA activity differently for CO&lt;sub&gt;2&lt;/sub&gt; and COS. Four soils of different pH were incubated in the dark or with a diurnal cycle for forty days to vary the abundance of native phototrophs. Fluxes of CO&lt;sub&gt;2&lt;/sub&gt;, CO&lt;sup&gt;18&lt;/sup&gt;O and COS were measured to estimate CA activity alongside the abundance of bacteria, fungi and phototroph genes. The abundance of soil phototrophs increased most at higher soil pH. In the light, the strength of the soil CO&lt;sub&gt;2&lt;/sub&gt; sink and the CA-driven CO&lt;sub&gt;2&lt;/sub&gt;-H&lt;sub&gt;2&lt;/sub&gt;O isotopic exchange rates correlated with phototroph abundance. COS uptake rates were attributed to fungi whose abundance was positively enhanced in alkaline soils but only in the presence of increased phototrophs. In addition we developed a metabarcoding approach to reveal the interactions of specific taxonomic groups incuding photosynthetic eukaryotic algae and cyanobacteria when exposed to light and their impact on flux rates. Our findings demonstrate that soil-atmosphere CO&lt;sub&gt;2&lt;/sub&gt;, COS and CO&lt;sup&gt;18&lt;/sup&gt;O fluxes are strongly regulated by the microbial community structure in response to changes in soil pH and light availability and support the idea that different members of the microbial community express different classes of CA, with different affinities to CO&lt;sub&gt;2&lt;/sub&gt; and COS.&lt;/p&gt;


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8175 ◽  
Author(s):  
Aleksandra Bielecka ◽  
Elżbieta Królak

Solidago canadensis L. is a drought-tolerant, invasive plant, characterized by a large biomass of underground and aboveground parts. The aim of this study was to assess the accumulation of manganese (Mn) and copper (Cu) in the roots and rhizomes and the stems, leaves, and inflorescence parts in S. canadensis from two locations that differed in soil pH, organic carbon, and Mn and Cu concentrations. The concentration of the metals in the samples was determined by the AAS method; the pH was determined by the potentiometric method; and the content of organic carbon was determined using Tiurin’s method. The concentration of Mn and Cu in the roots of S. candensis correlated with the concentrations of the metals in the soil without regard to the soil condition or its organic carbon content. With a low soil pH and organic carbon content, Mn accumulation per 1 ramet in the aboveground parts of S. canadensis consisted over 50% of the total Mn content in the plant. In neutral or alkaline soils, the amount of Mn per 1 ramet accumulated in underground parts was over 60%. Regardless of the soil conditions, about 35% of Mn accumulated in rhizomes. Approximately 60% of copper accumulated in the underground parts of S. candensis (45% in rhizomes) without regard to the soil reaction or organic carbon content. The ability of the plant to accumulate large amounts of metals disposes Solidago canadensis as a candidate for the phytoremediation of soils contaminated with heavy metals.


2012 ◽  
Vol 27 (4) ◽  
pp. 388-394
Author(s):  
Ana Maria Heuminski de Avila ◽  
Andrea de Oliveira Cardoso

Adverse weather conditions in critical periods of vegetative plant growth affect crop productivity, being a fundamental parameter for yield forecast. An increase in weather forecasting accuracy may be obtained by applying statistical correction to remove model bias. This study used statistical correction of ensemble forecasting with the atmospheric general circulation model (Center for Weather Forecasting and Climate Studies/Center for Ocean - Land - Atmosphere Studies - CPTEC/COLA) by mean error removal for three cities in the South of Brazil. Comparisons were made between corrected and original precipitation forecasts, and between these and data observed at their respective meteorological stations. Results showed that the applied statistical correction method may improve forecasting performance in some situations and that the term of forecast present high accuracy, indicating the importance of ensemble forecasting as an auxiliary tool in agricultural crop monitoring.


2004 ◽  
Vol 36 (1) ◽  
pp. 43
Author(s):  
Κ. Σικαλίδης ◽  
Ν. Καραγιαννίδης

Limestone, dolomitic stone, huntite, active magnesia and their mixtures as well as phosphorus containing gypsum, all by-products of various industrial activities, were investigated as soil amendments for acidic (pH 4.2 - 4.5) soils from Drama area, N. Greece and alkaline (pH 8.1 - 8.2) soils from Thermi area, N. Greece. Additions of 500 and 350 kg of the industrial by-products or their various mixtures tested, per 1000 sq.meters, improve the soil pH from the strong acidic area to 6.5- 7.5. Active magnesia increases the pH values above 8. Additions of 200 kg of mixtures of limestone and active magnesia per 1000 sq.meters, found to be able to increase the soil pH from 4.2 to around 6.5. These results were obtained within ten days from the day of application. Phosphorous containing gypsum, by-product of phosphoric fertilizers industry, was found to be able to decrease the soil pH from 8.1-8.2 down to 7.1. The results of this work suggest the possible use of the studied by-products as soil amendments for acidic and alkaline soils, respectively.


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