A SIMPLIFIED METHOD FOR LABORATORY SOIL ANALYSIS

ABSTRACT : The research goal was to develop a simplified method for estimating the available phosphorus for routine analysis. This study compared the measured Soil-P using the ICP-NaHCO 3 with the simplified extraction method (SM-P). The correlation (r=0.99) and the regression(using XLSTAT-Pro) were employed for comparing the data of available phosphorus content in soil samples for a variety of Moroccan soil types, with contrasted physicochemical characteristics: Ali Moumen, Oued Qibane, Ouled Said, Dower Hbata, Dower Lhfaya, and Had Ghoualem (are located using ArcGIS 10.1 and fertiMap). SM-P is most suited for soils with pH >= 7 and CaCO3 content above 5%. In this experiment, several parameters are modified, particle size, the type and degree of mechanical agitation ,the color development , and the adaptation of the reading at 860 nm, are improving the accuracy of P analysis, the high correlation of this method with ICP-NaHCO3 content can be an indication for it. The results of this experiment showed that SM-P can be the best method for predicting the available phosphorus, simple, quick, and easy to execute

Effect of Phosphogypsum on Faba Bean Yield and Heavy Metals Content under Saline Conditions

Salinity is one of the most severe abiotic stresses which causes significant losses to agricultural production, especially in arid and semi-arid areas. In the present study, we conducted a pots experiment to evaluate Phosphogypsum (PG) and Gypsum (G) as amendments and their effect on faba bean shoot and grain yield under saline conditions (soil ECe = 11.17 mS/cm, water EC = 1.5 mS/cm and water SAR = 4.2 meq/L). In addition, we investigated the safety of their application based on heavy metals content in the harvested grain. Our findings demonstrate that the use of PG as amendment for saline soil reclamation improved faba bean grain and biomass yield without affecting grain quality regarding heavy metal content

Effect of Phosphogypsum on Soil Physical Properties in Moroccan Salt-Affected Soils

Salinity is one of the most critical challenges for crop production and soil and water management in arid and semi-arid regions, such as a large area of Morocco. These regions are characterized by low rainfall with an erratic distribution, long drought periods, and high evaporation, resulting in salt accumulation in the superficial layer of the soil and soil and water degradation. Therefore, phosphogypsum (PG) could be a promising amendment to reduce the salinity effect and improve soil quality in salt-affected soils. In this context, the present study aimed to evaluate the effect of PG on the physical properties of Luvisols and Cambisols collected from salt-affected soils in four regions in Morocco: Chichaoua, Ras El Ain, Sidi Zouine, and Sed El Masjoune. The treatments consisted of different rates of PG (15, 30, and 45 t/ha), natural Gypsum (G) (15 t/ha), and control. Our findings revealed that PG application improved soil structure by promoting flocculant action provided by calcium. Linear regression indicated that Water Aggregate Stability (WAS) and PG doses were strongly correlated with a high coefficient of determination (R2 = 93.41%, p value < 0.05). Compared to the control, the overall efficiency of 45 t/ha of PG amendment reached 53%, 95%, and 36%, respectively, in Chichaoua, Ras El Ain, and Sed El Masjoune soils. PG application presented a positive effect on other soil physical properties (soil hydraulic properties, total porosity, and bulk density), especially for the soils of Chichaoua and Ras El Ain regions. The total porosity was increased by 8% with 45 t PG/ha in Ras El Ain soil, and in Chichaoua soil, the bulk density was 5% lower in the pot treated with 45 t PG/ha compared to the control. This study supports the use of PG as an amendment for reclaiming salt-affected soils through monitoring agronomic and environmental impacts

Effect of Phosphogypsum on Soil Physical Properties in Moroccan Salt-Affected Soils

Salinity is one of the most critical challenges for crop production and soil and water management in arid and semi-arid regions, such as a large area of Morocco. These regions are characterized by low rainfall with an erratic distribution, long drought periods, and high evaporation, resulting in salt accumulation in the superficial layer of the soil and soil and water degradation. Therefore, phosphogypsum (PG) could be a promising amendment to reduce the salinity effect and improve soil quality in salt-affected soils. In this context, the present study aimed to evaluate the effect of PG on the physical properties of Luvisols and Cambisols collected from salt-affected soils in four regions in Morocco: Chichaoua, Ras El Ain, Sidi Zouine, and Sed El Masjoune. The treatments consisted of different rates of PG (15, 30, and 45 t/ha), natural Gypsum (G) (15 t/ha), and control. Our findings revealed that PG application improved soil structure by promoting flocculant action provided by calcium. Linear regression indicated that Water Aggregate Stability (WAS) and PG doses were strongly correlated with a high coefficient of determination (R2 = 93.41%, p value < 0.05). Compared to the control, the overall efficiency of 45 t/ha of PG amendment reached 53%, 95%, and 36%, respectively, in Chichaoua, Ras El Ain, and Sed El Masjoune soils. PG application presented a positive effect on other soil physical properties (soil hydraulic properties, total porosity, and bulk density), especially for the soils of Chichaoua and Ras El Ain regions. The total porosity was increased by 8% with 45 t PG/ha in Ras El Ain soil, and in Chichaoua soil, the bulk density was 5% lower in the pot treated with 45 t PG/ha compared to the control. This study supports the use of PG as an amendment for reclaiming salt-affected soils through monitoring agronomic and environmental impacts

Effect of phosphogypsum application on aluminum speciation in acid pasture soils

Purpose: Legume establishment and persistence in New Zealand hill and high-country soils are largely limited by high soil acidity and associated aluminum (Al) toxicity. The present study aimed to evaluate the effect of four rates of phosphogypsum (0, 1, 3, and 9 t ha¯¹) on Al speciation in the soil solution and to examine which species are mostly impacting total dry matter (TDM) yield of lucerne. Methods: Glasshouse and incubation experiments were conducted using three acid soils with different exchangeable Al concentrations: Molesworth, Glenmore, and Lindis Peaks. The distribution of Al species was modeled using visual Minteq. Partial least square (PLS) regression was used to evaluate the relationships between Al³⁺ and other variables in the soil-soil solution system. Results: In the planted and incubated Molesworth soils, Al³⁺ and hydroxylated Al (Al–OH) fractions decreased significantly at 1 and 3 t of phosphogypsum ha−1 compared to 0 t ha¯¹. However, in the planted Glenmore and incubated Lindis Peaks soils, these two fractions remained unchanged. The contribution of variables in Al³⁺ concentration depended on the soil type. However, the loading plot of the whole soil data set (n = 62) showed that Al–OH, base saturation, soil/soil solution pHw, and exchangeable Al were the main explanatory variables for the variation in Al³⁺ concentration. The TDM yield of lucerne was better explained by Al³⁺ , Al-F, and Al-DOM than exchangeable Al. Conclusions: Reasonable amounts of phosphogypsum (1 to 3 t ha¯¹) can help to alleviate Al toxicity in acid soils (pH ≤ 5.3), but higher application rates should be avoided

Surface runoff and losses of phosphorus from hydrophobic pastoral soils

The impact of soil water repellency (SWR) on soil phosphorus (P) mobility in surface water runoff remains contentious. Although SWR may cause a significant increase in surface runoff, especially in post-summer rainfall events, whether it contributes to background phosphorus losses remains unclear. Surface runoff and P concentrations in runoff were measured on hilly Allophanic pastoral soils with different water repellency levels using seven runoff collectors. Phosphorus fertilizer was broadcasted at 18 kg P ha−1 in the summer over dry soils. Runoff volumes and P concentrations were measured after each natural rain event prompting surface runoff. The highest runoff/rainfall ratios were observed at the early rainfall events following the dry summer and then decreased significantly by the end of autumn and winter. The post-summer surface runoff correlation with SWR had an R2 of 0.46, and hydrophobic soils had significantly higher runoff ratios than wettable soils. Measurements of the dissolved reactive phosphorus (DRP) and total phosphorus (TP) in the surface runoff showed decreasing exponential trends, with the highest values recorded in the first runoff event following P fertilizer application, where over 90% of losses occurred (incidental losses). After the incidental loss phase, DRP concentrations were related to surface runoff ratio, soil P extractability by water, and SWR. Our data point to non-incidental TP loads being related to SWR (R2 = 0.53). The present results will improve the understanding of the SWR effect on surface runoff and will reconcile the controversy regarding its contribution to non-incidental P losses

Effect of Cadmium and Phosphorus Interaction on Tomato: Chlorophyll a Fluorescence, Plant Growth, and Cadmium Translocation

Cadmium (Cd) is considered one of the heavy metals disturbing plant biophysiological functions. The potential role of phosphorus (P) nutrition in the attenuation of Cd effects on photosynthetic efficiency, plant growth, and cadmium uptake has been investigated in hydroponically grown tomato. Two P nutrition regimes (P15: 15 mg l-1; P30: 30 mg l-1) were assessed in the presence or absence of Cd (Cd0: 0 μM; Cd25: 25 μM of CdCl2). The results showed a positive effect of P30 concentration on leaf chlorophyll content and chlorophyll a fluorescence compared to P15 treatment under Cd stress (Cd25). The disturbance of electron transfer caused by Cd at K and I-steps of OJIP transient was attenuated with sufficient P supply. P30 enhanced the performance index of photosystem II and the efficiency of electron transfer to electron acceptor at PSI acceptor side. Besides, increased P concentration improved root growth parameters and biomass accumulation in the presence of Cd. It was found that root tissues accumulated more Cd than shoots and Cd translocation was reduced with increasing P concentration. Our results reveal that Cd-P interaction induced a cascade of physiological and chemical changes in plants. An optimal P nutrition can attenuate Cd stress on plant by the promotion of nitrogen and potassium uptake, which in return improved photosynthesis efficiency, enhanced biomass accumulation and distribution, and minimized Cd accumulation and translocation in plant tissues. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature