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Linda Chalker-Scott, Associate Professor and Extension
Horticulturist, WSU Puyallup Research and Extension Center,
Washington State University , and Rich Guggenheim,
Horticulture Extension Educator, Canyon County Extension,
University of Idaho
Photo Credit: James St. John
Gypsum Use in Home Gardens and Landscapes
Gypsum has long been promoted as a soil
amendment for home gardeners who wish to
improve their soil structure. Popular books and
websites claim that gypsum will loosen compacted
soils and improve drainage. Gypsum is also claimed
to reduce soil acidity and cure blossom end rot.
Many of these claims are not supported with
scientific evidence. This publication will review the
scientific research behind the use of gypsum in
home gardens and provide readers with a set of
guidelines designed to improve problem soils and
promote plant health.
What is Gypsum?
Gypsum, or calcium sulfate, is a naturally occurring
mineral consisting of calcium and sulfur
(CaSO4, Figure 1). It is moderately soluble in water,
releasing positively charged calcium ions (Ca+2
cations) and negatively charged sulfate ions (SO4-2
Figure 1. Commercially available gypsum intended for garden
use. Photo by Rich Guggenheim.
What role does calcium play?
Calcium is an essential plant nutrient, required for
cell membrane function as well as for cell wall
structure. Calcium’s availability to plants is
influenced by the cation exchange capacity (CEC)
of soil, in which both clay and organic matter can
bind and release calcium. In this way, calcium also
plays a role in building soil structure by binding
clay particles together into aggregates. Soil
aggregates improve water movement by increasing
soil porosity.
What role does sulfate play?
Like calcium, sulfur plays an important role in plant
nutrition as an essential component of proteins.
Elemental sulfur (S) can acidify soils when it reacts
with soil water to form sulfuric acid (H2SO4). The
sulfate ion found in gypsum, however, does not
form sulfuric acid in the soil and has no effect on
soil pH.
Benefits of Gypsum Amendment
Documented Benefits
There is a robust collection of research articles on
the agricultural use of gypsum. This literature has
been recently reviewed elsewhere (Casby-Horton et
al. 2015; Zoca and Penn 2017). In general, the use
of gypsum on sodic (sodium containing) soils and
some heavy clay soils is beneficial to soil structure
and to plant health.
Gypsum can improve sodic soils, where excessive
levels of sodium ions (Na+) cause clay particles to
disperse rather than aggregate. This phenomenon
reduces soil porosity, creating poorly-drained soils
with heavy crusts (Figure 2). Because calcium can
readily bind to clay particles, the process of cation
exchange replaces sodium with calcium. The
sodium is leached through the soil and away from
plant roots, reducing soil crusts and improving
drainage. Plants benefit from the improved soil
structure as well as from the elimination of excess
sodium ions, which are toxic to most plants.
Figure 2. Salt buildup from salt-laden water percolating to the
surface and evaporating. Photo by Tim McCabe, USDA
Natural Resources Conservation Service.
Calcium’s affinity for binding sites on clay particles
sometimes improves the structure of heavy clay
soils by forming larger aggregates (peds). Peds
enhance soil drainage and aeration and reduce
compaction. In soils with a demonstrated calcium
deficiency, adding gypsum can improve plant
There are recent reports of possible environmental
benefits as well. When added to a clay soil, the
calcium in gypsum can bind phosphate, reducing
runoff of this aquatic pollutant (Kauppila and
Pietola 2013). Likewise, calcium can reduce
aluminum toxicity in plants growing in acidic soils
(Espejo-Serrano et al. 1999; Merino-Gergichevich
et al. 2010; Vizcayno et al. 2001; Zoca and Penn
Unsubstantiated Benefits
Most of the purported benefits of gypsum,
especially for home gardens, are not based on
scientific evidence.
Acidifies soil”: Gypsum does not change the
natural pH of soil; acidity and alkalinity are
significantly influenced by climatic factors, such as
rainfall and temperature, by local geology, and by
natural levels of organic matter.
Improves water holding capacity of soil”: Water
holding capacity of soils is closely tied to organic
matter and soil texture. Gypsum cannot change
either of these criteria, but it can increase water
movement through heavy clay soils by reducing
compaction and increasing ped formation.
Improves fertility of soil”: Other than being a
source of calcium and sulfur, gypsum has no effect
on inherent soil fertility. Plant nutrient availability
increases with increasing CEC, which is controlled
by clay content, organic matter, and pHnot
Cures blossom end rot of tomatoes and peppers”:
This claim is based on the false impression that
blossom end rot (Figure 3) is caused by a deficiency
in soil calcium. The development of blossom end
rot is directly influenced by water stressnot by
calcium levels. There is no research indicating any
relationship between gypsum addition and blossom
end rot suppression.
Figure 3. Blossom end rot of tomatoes is not caused by
calcium deficiency. Photo by Denny Schrock, Iowa State
Drawbacks of Gypsum Amendment
Without a professional soil test, it is impossible to
know the concentration of calcium in the soil, the
CEC, or pH. These are important variables in
determining what effects a gypsum addition will
have on plants or the environment. Excessive
addition or misuse of gypsum can create an
imbalance of soil minerals with unwanted results:
Gypsum can increase leaching of aluminum
and lead (McBride et al. 2013), which
detoxifies soils but contaminates nearby
watersheds (Lopez and Espejo 2002).
Gypsum can increase leaching of potassium
(Zoca and Penn 2017), iron and manganese
(Vidal et al. 2003), and magnesium (Ritchey
and Snuffer 2002; Warren and Shelton 1993;
Zoca and Penn 2017) leading to deficiencies
of these nutrients in plants on site and
contaminating nearby watersheds.
Gypsum applied to sandy soils can depress
phosphorus, copper, and zinc transport (Zhu
and Alva 1994).
Gypsum can have negative effects on
mycorrhizal inoculation of roots (Habte and
Soedarjo 1995), which may account for
reported negative effects of gypsum on tree
seedling establishment and survival (Bakker
et al. 1999; Singh et al. 1997).
Recommendations for Gypsum Use in
Home Gardens and Landscapes
There are few articles relevant to gypsum use in
urban areas, and none specific to home gardens and
landscapes. We do know, however, that urban
soilsincluding those in home gardens and
landscapesare vastly different from those in
natural areas or agricultural situations. They often
consist of abrupt layers, which are not amendable
with gypsum improvement.
At this time our understanding of how gypsum
affects soils and plants is inconsistent and
incomplete. Plant species, soil type, and rainfall
regime all interact with the physical and chemical
changes that gypsum can effect on soils (Zoca and
Penn 2017). Even in agriculture there is not yet “a
suitable recommendation that considers different
soil (type, chemical, and physical characteristics),
rainfall rates, temperature, crops, and cropping
systems” (Zoca and Penn 2017). For home
gardeners, this means there are no broad, science-
based guidelines for applying gypsum. Your county
Extension personnel should be consulted for local
recommendations based on field data, if available.
Action Items for Gardeners
Collect soil samples (as described in Fery
and Murphy, 2013) for professional testing
(Figure 4) before applying gypsum or any
fertilizer. Be sure to ask for pH, levels of
basic plant nutrients, and sodium.
Figure 4. A soil test with nutrients, pH, and sodium levels
reported. Photo by Rich Guggenheim.
Do not use the calcium-to-magnesium ratio
from your soil test to determine gypsum use.
There is no indication that this ratio is
relevant to gypsum application rates (Zoca
and Penn 2017).
Estimate your soil texture type with the
ribbon test (Cogger 2010). This will help
you determine if your clay content is high
enough (>40%) that gypsum might be
Unless calcium is deficient and pH is in the
optimal range, do not add gypsum. If sulfur
is needed, use ammonium sulfate or
potassium sulfate instead.
Use a coarse woody mulch on landscape
soils to reduce compaction, improve
aeration, and conserve soil water naturally
(Chalker-Scott 2015).
Keep vegetable gardens well hydrated
during the growing season to avoid water
stress and blossom end rot.
Literature Cited
Bakker, M.R., R. Kerisit, K. Verbist, and C. Nys.
1999. Effects of Liming on Rhizosphere Chemistry
and Growth of Fine Roots and of Shoots of Sessile
Oak (Quercus petraea). Plant and Soil
Casby-Horton, S., J. Herrero, and N.A. Rolong.
2015. Gypsum SoilsTheir Morphology,
Classification, Function, and Landscapes. Advances
in Agronomy 130:231290.
Chalker-Scott, L. 2015. Using Arborist Wood Chips
as a Landscape Mulch. WSU Extension Fact Sheet
FS160E. Washington State University.
Cogger, C. 2010. WSU Soil: Home Soil Sampling,
YouTube video, 9:08.
Espejo-Serrano, R., J. Santano-Arias, and P.
Gonzaléz-Fernandéz. 1999. Soil Properties That
Affect Sulphate Adsorption By Palexerults in
Western and Central Spain. Communications in Soil
Science and Plant Analysis 30(910):15211530.
Fery, M., and E. Murphy. 2013. A Guide to
Collecting Soil Samples for Farms and Gardens.
OSU Extension Fact Sheet EC628.
Habte, M., and M. Soedarjo. 1995. Mycorrhizal
Inoculation Effect in Acacia mangium Grown in an
Acid Oxisol Amended With Gypsum. Journal of
Plant Nutrition 18(10):20592073.
Kauppila, R. and L. Pietola. 2013. Gypsum to
Improve Soil Structure and to Reduce Phosphorus
Loss. Proceedings of the International Fertiliser
Society No.741 (20 pp.).
Lopez, A., and R. Espejo. 2002. Study of
Ammonium Contamination in Leachates from an
Ultisol Following Application of Various Types of
Amendment. Water, Air, and Soil Pollution
McBride, M.B., T. Simon, G. Tam, and S. Wharton.
2013. Lead and Arsenic Uptake by Leafy
Vegetables Grown on Contaminated Soils: Effects
of Mineral and Organic Amendments. Water, Air,
and Soil Pollution 224(1):1378.
Merino-Gergichevich, C., M. Alberdi, A.G. Ivanov,
and M. Reyes-Diaz. 2010. Al3+- Ca2+ Interaction in
Plants Growing in Acid Soils: Al-phytotoxicity
Response to Calcareous Amendments. Journal of
Soil Science and Plant Nutrition 10(3):217243.
Ritchey, K.D., and J. D. Snuffer. 2002. Limestone,
Gypsum, and Magnesium Oxide Influence
Restoration of an Abandoned Appalachian Pasture.
Agronomy Journal 94:830839.
Singh, G., J.C. Dagar, and N.T. Singh. 1997.
Growing Fruit Trees in Highly Alkali Soilsa Case
Study. Land Degradation and Development
Vidal, M., A. Lopenj, R. Espejo, and R. Blazquez.
2003. Comparative Analysis of Corrective Action
of Various Liming and Gypsum Amendments on a
Palexerult. Communications in Soil Science and
Plant Analysis 34(56):709723.
Vizcayno, C., M.T. Garcia-Gonzalez, Y. Fernandez-
Marcote, and J. Santano. 2001. Extractable Forms
of Aluminum as Affected by Gypsum and Lime
Amendments to an Acid Soil. Communications in
Soil Science and Plant Analysis 32(1314):2279
Warren, S.L., and J.E. Shelton. 1993. Olivine: a
Potential Slow-Release Magnesium Source for
Nurseries. Journal of Environmental Horticulture
Zhu, B., and A.K. Alva. 1994. The Effect of
Gypsum Amendment on Transport of Phosphorus in
a Sandy Soil. Water, Air, and Soil Pollution 78(3
Zoca, S.M., and C. Penn. 2017. An Important Tool
with No Instruction Manual: a Review of Gypsum
Use in Agriculture. Advances in Agronomy 144:1
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intended. Published September 2018.
... Jipsin çok killi topraklarda da iyileştirici olarak kullanıldığı bilinmektedir. Jips, çok killi toprakların, özellikle de ağır hava şartlarına maruz kalmış veya yoğun mahsul üretimine tabi olan toprakların yapısını geliştirmekte, hidrolik iletkenliğini artırmakta ve verimliliğini etkili bir şekilde değiştirmektedir (Oster & Frankel, 1980;Karahan & Özşahin, 2016;Chalker-Scott, 2018). ...
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Structured Abstract: The productivity and usage capabilities of the soils, which have been used extensively since ancient times, are decreasing day by day. In this respect, experts and scientists have gone to different inventions and quests to solve this problem. As the most practical solution to increase productivity again, natural rocks, which are found in nature and contain various minerals, are considered. Namely, each rock has different physical and chemical properties and creates other ecological properties in its environment. In this context, gypsum is one of the rocks that form important habitats in terms of environmental diversity. Due to the different minerals in gypsum, a white chemical sedimentary stone, its natural colors may also bedifferent. Thanks to its use in agriculture and soil regulation, gypsum has many advantages such as optimum yield, crop quality, creating a favorable environment for plant growth, and using it as a water purifier in ponds with its processed form. The demand for gypsum is increasing day by day due to its vast usage area, advantages, and the reasons such as being easily accessible and economical. Purpose In this research, the study's primary purpose is to determine how gypsum affects ecology, its usage areas, and its effects on nature. For this purpose, to provide information about gypsum ecology, it is first necessary to research and classify the usage areas of gypsum. When the literature is reviewed, it is seen that few studies include gypsum ecology and gypsum usage areas together. The research has an essential place in contributing to this small number of studies in the literature and creating a data source for the studies planned to be done in the future. Method This research is a systematic review type study within the framework of the primary research method. "Systematic reviews, comprehensive and detailed scanning of studies made with similar methods in a field; It is a research approach based on the determination of the studies to be included in the review using various selection criteria, and a structured and comprehensive quality assessment and synthesis of the determined studies" (Yılmaz 2021). In this context, national or international articles, postgraduate theses, published books, as well as research in foreign indexed databases were also used. It is of great importance for the reliability of the study to obtain the sources, evaluate them and systematically summarize the data. When searching in digital environments, the keywords "gypsum ecology," "use areas of gypsum," and "effects of gypsum on plants" in Turkish search, and "gypsum ecology," "gypsum usage areas," and "effects of gypsum on plants" in English search. According to Pautasso (2013), obtaining data from current studies is essential while conducting a compilation study. However, previous studies should not be ignored. Since this research was carried out as a compilation, information about the ecology of gypsum and the usage areas of gypsum theoretically in the literature about the general properties, usage areas, and ecology of gypsum was searched, and information was tried to be presented, interpreted, and concluded. Findings (or Conclusions) Gypsum is the essential product that helps regulate the soil, improve its structure, and increase its quality and yield. Thanks to the use of gypsum in agriculture and as a soil improvement agent, it has many advantages such as optimum yield, crop quality, creating a favorable environment for plant growth, and using it as a water purifier in ponds with its processed form. In this respect, it is seen that gypsum fields are both a critical gene resource center in the world and an economical and ergonomic improvement material if they are included in the soil structure. Although gypsum has many advantages, care should be taken during use. First of all, it is essential to determine whether the soil will react to gypsum, define the usage area and amount of use, and get help from experts. When used with this awareness, it will be seen that gypsum has a potential power, not a hostile place in nature. Suggestions Therefore, necessary studies should be carried out and contribute to the economy as employment in various sectors. In addition, gypsum areas should be determined. The boundaries of the regions where they are located should be selected. A detailed inventory of the climate, landforms, agricultural methods, and grown products should be taken. In line with these data, how much and how often gypsum will be used in which products should be determined. Within the scope of this study, general information about the use of gypsum both in the area where it is located and outside the location where it is located is given. In this context, it is suggested that the research be studied in more local areas, and new gypsum, industry branches, and employment branches should be created.
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Home gardening is increasingly popular, particularly during a global pandemic when many people are confined to home and are spending more time outside. Novice and experienced gardeners alike are likely to access agricultural production information that is not necessarily relevant to their home gardens or landscapes. Specifically, there are soil fertility guidelines intended for intensive, monocultural crop production that can harm plants, soil biota, and nearby aquatic systems when applied to a home garden situation. This article will address six common misperceptions about managing soil nutrition in nonagricultural situations.
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High aluminum (Al) concentrations as Al3+ represent an important growth and yield limiting factor for crops in acid soils (pH ≤ 5.5). The most recognized effect of Altoxicity in plants is observed in roots. However, damages in the upper parts (including stem, leaves and fruits) may also be present. In addition, Al-toxicity triggers an increase in reactive oxygen species (ROS), causing oxidative stress that can damage the roots and chloroplasts, decreasing normal functioning of photosynthetic parameters. Altoxicity may also increase or inhibit antioxidant activities, which are responsible to scavenge ROS. As result of the negative effects of toxic Al, root metabolic processes, such as water and nutrient absorption, are disturbed with a concomitant decrease in calcium (Ca) uptake. Ca plays a fundamental role in the amelioration of pH and Altoxicity through Al-Ca interactions improving physiological and biochemical processes in plants. Ca is a useful amendment for correcting these negative effects on crops growing in acid soils. This is an agronomic practice with alternatives, such as limestone or gypsum. There is little information about the interaction between amendments and Al-toxicity in physiological and biochemical processes in crops. Thus, the main objective of this review is to understand the interactions between Al3+ and Ca amendments and their effects on the physiology and biochemical responses in crops growing in acid soils.
Fraser photinia, ‘Plumosa Compacta Youngstown’ juniper and ‘Hino-Crimson’ azalea were grown in pine bark amended with a factorial combination of five rates (0, 0.9, 1.8, 3.6 and 7.2 kg/m3) (0, 1.5, 3, 6 and 12 lbs/yd3) of olivine, a magnesium ortho silicate containing 27% Mg and four particle sizes of olivine. Calcium carbonate (38% Ca) at 2.4 kg/m3 (4 lbs/yd3) was incorporated into all olivine treatments. A separate treatment utilizing 4.2 kg/m3 (7 lbs/yd3) dolomitic limestone (22% Ca, 11% Mg) was also included to serve as a comparison to dolomitic limestone. In general, Mg concentration in the media increased with increasing olivine rate and decreasing particle size. Media P, K and Ca concentration and pH were not affected by olivine rate or particle size, nor were they significantly different from the treatment containing dolomitic limestone. Foliar Mg increased with increasing olivine rate in all species. Foliar K decreased with increasing olivine rate for ‘Hino-Crimson’ azalea and Fraser photinia. Top dry weight of ‘Plumosa Compacta Youngstown’ juniper was not affected by olivine rate or particle size while top dry weight of ‘Hino-Crimson’ azalea and Fraser photinia increased quadratically with increasing olivine rate, with the maximum occurring at 0.9 kg/m3 (1.5 lbs/yd3) and 1.8 kg/m3 (3.0 lbs/yd3), respectively. These maximum top dry weights were significantly heavier than plants grown with dolomitic limestone.
Gypsum soils are both a problem and a puzzle, which is precisely why they deserve attention. Gypseous (high-gypsum) soils generally occupy sparsely populated land with minimal land use intensity in arid and semiarid climates. Gypsum content in agricultural soils results in restricted water and nutrient retention and the potential for dissolution piping, primarily in response to irrigation. The corrosive effects of gypsum soils on concrete, metal, and building materials are also problematic. On the other hand, understanding the genesis and function of gypsiferous (low-gypsum) and gypseous soils is interesting and challenging, and our grasp of processes involved in the formation and behavior of these soils is critical for proper management for agricultural, rangeland, engineering, and construction purposes. The objective of this review was to examine the physical and chemical properties of gypsum and the impacts of these properties in the soil environment. The particular properties that gypsum presence imparts to soils affect soil development, including soil morphology. Accumulations of pedogenic gypsum influence water-holding capacity, nutrient and water availability for plants, root growth, and the standard concepts of soil texture and rupture resistance. Gypsum precipitation is also affected by the presence of more soluble salts. The development of physicochemical models that explain the formation and function of gypsiferous and gypseous soils is necessary if we hope to properly manage and maintain these unusual soils and their landscapes.
To assess strategies for mitigating Pb and As transfer into leafy vegetables from contaminated garden soils, we conducted greenhouse experiments using two field-contaminated soils amended with materials expected to reduce metal phytoavailability. Lettuce and mustard greens grown on these soils were analyzed by ICP-MS, showing that some Pb and As transfer into the vegetables occurred from both soils tested, but plant Pb concentrations were highly variable among treatment replicates. Soil-to-plant transfer was more efficient for As than for Pb. Contamination of the leaves by soil particles probably accounted for most of the vegetable Pb, since plant Pb concentrations were correlated to plant tissue concentrations of the immobile soil elements Al and Fe. This correlation was not observed for vegetable As concentrations, evidence that most of the soil-to-plant transfer for this toxic metal occurred by root uptake and translocation into the above-ground tissues. A follow-up greenhouse experiment with lettuce on one of the two contaminated soils revealed a lower and less variable foliar Pb concentration than observed in the first experiment, with evidence of less soil particle contamination of the crop. This reduced transfer of Pb to the crop appeared to be a physical effect attributable to the greater biomass causing reduced overall exposure of the above-ground tissues to the soil surface. Attempts to reduce soil Pb and As solubility and plant uptake by amendment at practical rates with stabilizing materials, including composts, peat, Ca phosphate, gypsum, and Fe oxide, were generally unsuccessful. Only Fe oxide reduced soluble As in the soil, but this effect did not persist. Phosphate amendment rapidly increased soil As solubility but had no measurable effect on either soil Pb solubility or concentrations of Pb or As in the leafy vegetables. The ineffectiveness of these amendments in reducing Pb transfer into leafy vegetables is attributed in this study to the low initial Pb solubility of the studied soils and the fact that the primary mechanism of Pb transfer is physical contamination.
The beneficial action of gypsum in suppressing aluminum (Al) toxicity in Bt horizons of Ultisols is related to the self‐liming effect of the adsorption of sulphate (SO4 ) ion. The relationship between SO4 adsorption by gypsum‐amended soils and some components and properties of 38 surface and subsurface horizons from seven Palexerults in western and central Spain was analyzed. The highest correlations of maximal SO4 adsorption as determined from langmuir isotherms were with clay, free iron oxyhydroxides (Fedcb), and exchangeable Al contents, and pH. Liming reduces SO4 ’ ion adsorption; consequently, the joint application of limestone and gypsum to the surface of these soils results in increased availability of gypsum for the subsurface horizons.
The effect of gypsum amendment on transport of phosphorus (P) in a Pineda sand (loamy, silicious, hyperthermic Arenic Glossaqualf) was investigated in a leaching column experiment. Phosphorus was either placed on the surface of the soil or mixed with the surface 2 cm depth of soil in the column. Gypsum amendment decreased the transport of P in soil. Compared to the unamended soil, transport of P decreased by 35 and 54% in soils amended with 4.5 and 9.0 M.T./ha gypsum, respectively. The transport of P was further decreased by 74% when P was premixed with the surface 2 cm of soil. The transport of P was not influenced by the SO4 ion from gypsum amendment. Instead, formation of Ca-P precipitate appeared to be responsible for the decreased transport of P in the gypsum-amended soil.
Glomus aggregatum and Acacia mangium were interacted in an acid manganese (Mn)‐rich oxisol unamended or amended with hydrated lime [Ca(OH)2] or gypsum (CaSO4) at soil phosphorus (P) concentrations considered optimal for mycorrhizal host growth. Vesicular‐arbuscular mycorrhizal fungal (VAMF) colonization as well as VAMF function was significantly curtailed if soil was unamended with gypsum or lime. The highest mycorrhizal inoculation effect (MIE) was observed in the soil treated with gypsum at the rate of 0.32 g of calcium (Ca)/kg followed by the limed soil. Higher concentrations of gypsum deleteriously affected VAMF infectivity and effectivity. The first increment of gypsum compensated for part of the VAMF colonization and for all of the mycorrhizal inoculation effect that was lost due to low pH. The better MIE observed in the gypsum treated soil compared to that which was amended with lime suggests that the sensitivity of the acacia‐VAMF association to soil acidity was more a function of Ca inadequacy than it was of pH or associated increases in Mn concentration.
The influence of gypsum or lime + gypsum amendments on various extractable forms of aluminum (Al) in a reconstructed acid soil (plinthic Palexerult) was investigated. The addition of gypsum depolymerized non-hydrolysable carbon (C) and increased the extraction of Al bound to organic matter. The application of gypsum or lime + gypsum lowered the levels of exchangeable Al; also, the low proportion of Al in outflow solutions suggests the immobilization of Al as a solid phase. Except for exchangeable Al, the gypsum amendment increases the proportion of all forms of Al extracted (bound to organic matter, sorbed to, oxalate and citrate) with various selected reagents relative to unamended samples. The amount of Al extracted increases with increase of gypsum added. The gypsum or lime + gypsum amendments increased soil productivity.
The performance of 10 fruit species, namely pomegranate (Punica granatum), guava (Psidium guajava), sapota (Achras japota), baelpather (Aegle marmelos), amla (Emblica officinalis), ber (Zizyphus mauritiana), karaunda (Carissa carandas), date palm (Phoenix dactyleform), jamun (Syzygium cuminii) and imli (Tamarindus indica), as affected by site preparation and amendment use, was evaluated in a replicated field trial established in 1992 in a highly alkali soil (pH 10·5) at the Bichhian experimental farm of the Central Soil Salinity Research Institute, Karnal. The treatments involved two site preparation methods: (1) augerholes of 20–25 cm diameter and 160–180 cm deep made in the centre of 45 cm×45 cm pits in the main plot and (2) pits of 90 cm×90 cm×90 cm; variable amendments composition in the subplot and fruit species in the sub-subplots. Growth observations recorded 26 months after planting showed that survival, height and girth of all species remained unaffected owing to site preparation techniques and amendment use. Irrespective of planting techniques and amendment use, jamun, guava, ber and imli performed best. Date palm and baelpather performed poorly. Initial growth of sapota was satisfactory, but it was found highly sensitive to frost. Similarly, pomegranate which was performing exceedingly well was found very sensitive to prolonged water stagnation. This 3-year study indicated that out of 10 species tried, about half a dozen fruit plants can be established in alkali soils after following appropriate site preparation methods and better management practices. Established species came to bearing between 18 and 24 months after planting, but the fruits were damaged by prolonged water stagnation during the monsoon season and chilling temperatures of the 1994–95 winter. This study further indicated that the augerhole method of root bed preparation, is an economical, less laborious and faster way of planting fruit trees than is the pit method. The experiment will be continued to study treatment effects on fruit production and quality before making final recommendations. © 1997 John Wiley & Sons, Ltd.
The composition of leachates from an Ultisol reconstructed inlysimeters and amended with limestone, sugar foam waste and gypsum rock was studied. The typical rainfall of the area fromwhich the soil was collected was simulated under laboratory conditions over a five-month period. The soil samples treated with gypsum behaved markedly differently from the rest. Thus, the samples amended with gypsum gave leachates with substantially increased ammonium contents that might result in contamination of aquifers. The gypsum-treated samples alsoexhibited marked differences in pH, EC and the Ca, Mg, Na andK contents from the rest.