Application Of Rock Phosphate Research Articles

Effect of rock phosphate direct application on tropical legumes under different soil types of Sudan Savanna

ABSTRACT Direct application of low-grade rock phosphate (RP) is a less expensive alternative than the application of chemical phosphorus (P) for small holders relying on nutrient-deficient weathered soils. However, the effect of RP application on growth and yield is unstable for different crop species and soil water conditions. To identify legume species effective for RP direct application, five tropical legumes (cowpea, groundnut, bambara nut, mung bean, and soybean) were tested under two soil types with different water-holding capacities in Sudan Savanna; Lixisols and Plinthosols. The experiment was conducted under three conditions of P treatment, namely, RP application, triple super phosphate (TSP) application, and no phosphorus fertilizer application (0P). Under RP treatment, higher grain yield was obtained in Lixisols, which had a higher water-holding capacity. However, the yield increase was suppressed in the year with more rainfall owing to drastic changes in the soil moisture content, which caused excessive soil moisture stress during vegetative growth periods. Among the five legume species, cowpea and groundnut showed higher grain yields under the RP treatment than did other species. RP application increased shoot biomass but caused small changes in the shoot P and N concentrations. Soybean in Plinthosols had the highest yield ratio of RP/0P, but the absolute yield was low because of the insufficient soil water availability caused by the low water-holding capacity. RP direct application can assist shoot growth and yield, but it rarely compensates for basal yield differences between soil types and among legume species.

Development of bacteria-based bioorganic phosphate fertilizer enriched with rock phosphate for sustainable wheat production.

Phosphorous (P) is a limiting macronutrient for crop growth. Its deficiency prevents plant development leading to an extensive use of phosphatic fertilizers globally. Bio-organic phosphate (BOP) fertilizer provides a sustainable approach to optimize nutrient availability, enhance crop yield, and mitigate the negative impacts of chemical fertilizers on the environment. Therefore, the present study integrates the application of heat-tolerant phosphate-solubilizing bacteria, rock phosphate, and organic materials for the development of BOP. For this purpose, potential heat-tolerant phosphate-solubilizing bacteria (PSB) were isolated from major wheat-growing areas of southern Punjab. Five isolates were the efficient phosphate solubilizers based on in vitro phosphate-solubilizing activity (291-454 μg ml-1 and 278-421 μg ml-1) with a concomitant decrease in pH (up to 4.5) at 45°C and 50°C, respectively. These PSB were used for the development of potential consortia that are compatible and showed high P solubilization. In planta evaluation of these PSB consortia in a pot experiment under net house conditions showed that consortium-2 had a favorable impact on growth parameter with enhanced grain yield (9.63 g plant-1) and soil available P (10 μg g-1) as compared with 80% uninoculated control. The microcosm study was conducted to evaluate PSB consortium-2 integrated with carrier material (plant material and filter mud) and rock phosphate as BOP increased total phosphorous (14%) as compared with uninoculated controls. Plant-based BOP showed higher viable count (3.5 × 108°CFU) as compared with filter mud-based BOP. Furthermore, the effect of BOP on wheat growth parameters revealed that BOP showed a promising influence on grain yield (4.5 g plant-1) and soil available P (10.7 μg g-1) as compared with uninoculated 80 and 100% controls. Principle component analysis (PCA) further validates a positive correlation between BOP with grain weight and plant height and soil available P as compared with both 80 and 100% controls. For the first time, this study reports the combined application of bio-organic phosphate fertilizer and heat-tolerant PSB, which offers an eco-friendly option to harvest better wheat yield with low fertilizer input.

Rock Phosphate and Biochar Effects on Greenhouse Gas Emissions and Soil Fertility in Southern Alberta Potato Field

The application of biochar soil amendment and rock phosphate fertilizer to the soil could lead to achieving net zero emissions and food security; however, the effectiveness of using biochar and rock phosphate in southern Alberta brown chernozemic soil is not yet assessed. In the first trial of this study, varying levels of urea (N), with varying levels of biochar (B) were applied. The same level of rock phosphate (RP) and triple super phosphate (TSP) were applied to compare efficiency of the two fertilizers. The second trial involved applying the same nutrients, but with higher levels than the first trial. The results indicated that the fertilizer application rates did not affect the growth and yield of potatoes because of the application rates of the fertilizer and fertility status of the soil, whereas in the second trial, TSP and RP treatments had the same growth and yield. Furthermore, the high application rate of nitrogen fertilizer and RP with or without biochar in the potato plot emitted high nitrous oxide gas emissions while the low application rate of nitrogen fertilizer and RP kept the carbon dioxide in the soil. Nevertheless, in the second experiment, the application of biochar and rock phosphate reduced nitrous oxide and carbon dioxide emissions. We observed high residual nitrogen and manganese nutrients after harvest in the plot treated to rock phosphate and biochar. Therefore, rock phosphate and biochar have the potential to increase food production and mitigate climate change.

Efficiency of phosphate fertilizers containing growth promoters in plant fertilization

Optimizing water and nutrient absorption in plants can be achieved through a practical strategy: the combination of plant growth promoters (PGPs) with phosphate fertilizers. This synergistic approach holds promise for enhancing agricultural productivity and sustainability. The objectives of this work were to produce new phosphate fertilizers containing PGPs and to evaluate the efficiency in promoting the growth of the roots and shoots and increased phosphorus (P) uptake of plants. The fertilizers produced contained reactive natural phosphate rock from Morocco and PGPs indole-3-butyric acid, humic substances or Trichoderma afroharzianum, and a control fertilizer, without adding PGPs. The agronomic efficiency of this fertilizers were evaluated in two contrasting soils. The additional treatment with the monoammonium phosphate was included. The experimental unit consisted of rhyzobox containing 350 cm3 of soil, where a soybean plant was grown. Thirty days after sowing, the root length, average root diameter, root tips, and fine roots were measured using WinRHIZO software. The dry matter and P content of the roots and shoots were determined. PGPs have a great potential to increase the efficiency of P absorption by plants and the photosynthetic rate, and have a great potential to increase phosphorus use efficiency. The effects of PGPs were observed in the architecture of the root system, leaf area, and increased P content by plants. In sandy soil, the application of phosphate rock containing humic substances, Trichoderma afroharzianum, and indole-3-butyric increases the total phosphorus uptake by 26.5%, 16.3%, and 12.2%, respectively.

Assessing the influence of diverse phosphorus sources on bacterial communities and the abundance of phosphorus cycle genes in acidic paddy soils.

The impact of chemical fertilizers on soil microbial communities is well acknowledged. This study assesses the influence of various phosphorus sources on soil bacterial composition, abundance, and Phosphorus Cycle Gene Abundance. Three phosphorus sources (natural phosphate rock, triple super phosphate (TSP), and chemical fertilizer NPK) were field tested following two rice cultivation cycles. Soil samples were subsequently collected and analyzed for bacterial groups and phosphorus cycle genes. Results indicated that the bacterial community composition remained consistent, comprising five main phyla: Firmicutes, Actinobacteria, Proteobacteria, Halobacterota, and Chloroflexia, regardless of fertilizer type. NPK fertilizer significantly reduced the relative abundance of Chloroflexia by 19% and Firmicutes by 16.4%, while increasing Actinobacteria and Proteobacteria by 27.5 and 58.8%, respectively. TSP fertilizer increased Actinobacteria by 27.1% and Halobacterota by 24.8%, but reduced Chloroflexia by 8.6%, Firmicutes by 12.6%, and Proteobacteria by 0.6%. Phosphate rock application resulted in reductions of Chloroflexia by 27.1%, Halobacterota by 22.9%, and Firmicutes by 6.2%, alongside increases in Actinobacteria by 46.6% and Proteobacteria by 23.8%. Combined application of TSP, NPK, and phosphate rock led to increases in Proteobacteria (24-40%) and Actinobacteria (13-39%), and decreases in Chloroflexia (5.2-22%) and Firmicutes (6-12.3%) compared to the control (T0). While the different phosphorus sources did not alter the composition of phosphorus cycle genes, they did modulate their abundance. NPK fertilizer did not significantly affect ppK genes (57-59%) but reduced gcd (100 to 69%), 3-phytase (74 to 34%), appA (91 to 63%), and phoD (83 to 67%). Phosphate rock reduced appA and gcd by 27 and 15%, respectively, while increasing 3-phytase by 19%. TSP decreased ppK and phoD by 42 and 40%, respectively, and gcd and appA by 34 and 56%, respectively. Combined fertilizers reduced appA (49 to 34%), 3-phytase (10 to 0%), and gcd (27 to 6%), while increasing ppK (72 to 100%). Among tested phosphorus sources, natural phosphate rock was best, causing moderate changes in bacterial composition and phosphorus genes, supporting balanced soil microbial activity. These findings highlight the complex interactions between fertilizers and soil microbial communities, underscoring the need for tailored fertilization strategies to maintain soil health and optimize agricultural productivity.

Influence of Increase in Phosphorus Supply on Agronomic, Phenological, and Physiological Performance of Two Common Bean Breeding Lines Grown in Acidic Soil under High Temperature Stress Conditions.

Many common bean (Phaseolus vulgaris L.) plants cultivated in areas of the world with acidic soils exhibit difficulties adapting to low phosphorus (P) availability, along with aluminum (Al) toxicity, causing yield loss. The objective of this study was to evaluate the influence of an increase in P supply level on the agronomic, phenological, and physiological performance of two common bean breeding lines grown in acidic soil, with low fertility and under high temperature conditions, in a screenhouse. A randomized complete block (RCB) design was used under a factorial arrangement (five levels of P × 2 genotypes) for a total of 10 treatments with four replications. The factors considered in the experiment were: (i) five P supply levels (kg ha-1): four levels of P0, P15, P30, and P45 through the application of rock phosphate (RP), and one P level supplied through the application of organic matter (PSOM) corresponding to 25 kg P ha-1 (P25); and (ii) two advanced bean lines (BFS 10 and SEF10). Both bean lines were grown under the combined stress conditions of high temperatures (day and night maximum temperatures of 42.5 °C/31.1 °C, respectively) and acidic soil. By increasing the supply of P, a significant effect was found, indicating an increase in the growth and development of different vegetative organs, as well as physiological efficiency in photosynthesis and photosynthate remobilization, which resulted in higher grain yield in both bean lines evaluated (BFS 10 and SEF10). The adaptive responses of the two bean lines were found to be related to phenological adjustments (days to flowering and physiological maturity; stomatal development), as well as to heat dissipation strategies in the form of heat (NPQ) or unregulated energy (qN) that contributed to greater agronomic performance. We found that, to some extent, increased P supply alleviated the negative effects of high temperature on the growth and development of the reproductive organs of bean lines. Both bean lines (BFS 10 and SEF 10) showed adaptive attributes suited to the combined stress conditions of high temperature and acidic soil, and these two lines can serve as useful parents in a bean breeding program to develop multiple stress tolerant cultivars.

Improved efficiency of Sedum lineare (Crassulaceae) in remediation of arsenic-contaminated soil by phosphate-dissolving strain P-1 in association with phosphate rock.

The selection of appropriate plants and growth strategies is a key factor in improving the efficiency and universal applicability of phytoremediation. Sedum lineare grows rapidly and tolerates multiple adversities. The effects of inoculation of Acinetobacter sp. phosphate solubilizing bacteria P-1 and application of phosphate rock (PR) as additives on the remediation efficiency of As-contaminated soil by S. lineare were investigated. Compared with the control, both the single treatment and the combination of inoculation with strain P-1 and application of PR improved the biomass by 30.7-395.5%, chlorophyll content by 48.1-134.8%, total protein content by 12.5-92.4% and total As accumulation by 45.1-177.5%, and reduced the As-induced oxidative damage. Inoculation with strain P-1 increased the activities of superoxide dismutases and catalases of S. lineare under As stress, decreased the accumulation of reactive oxygen species in plant tissues and promoted the accumulation of As in roots. In contrast, simultaneous application of PR decreased As concentration in S. lineare tissues, attenuated As-induced lipid peroxidation and improved As transport to shoots. In addition, the combined application showed the best performance in improving resistance and biomass, which significantly increased root length by 149.1%, shoot length by 33%, fresh weight by 395.5% and total arsenic accumulation by 159.2%, but decreased the malondialdehyde content by 89.1%. Our results indicate that the combined application of strain P-1 and PR with S. lineare is a promising bioremediation strategy to accelerate phytoremediation of As-contaminated soils.

An Application of Rock Phosphate Increased Soil Cadmium Contamination and Hampered the Morphophysiological Growth of Brassica campestris L

An Application of Rock Phosphate Increased Soil Cadmium Contamination and Hampered the Morphophysiological Growth of Brassica campestris L

Inference of Rock Phosphate, Phosphorus Solubilizing Bacteria and Lime on Phosphorus Content and Economic Yield of Green Gram

Aim: To study the effect of Rock Phosphate, Phosphorus Solubilizing Bacteria, and Lime on phosphorus content in the soil, Phosphorus Uptake, and Economic yield of green gram (var. DGGS-4).
 Study Design: This experiment was conducted through a completely randomized design with 10 treatments and 3 replications.
 Place and Duration of Study: The research was conducted at the Department of Soil Science and Agricultural Chemistry, Central Agricultural University, Imphal between February 2019- November 2019.
 Methodology: Available phosphorus content in soil was estimated spectrophotometrically by Bray and Kurtz No. 1 method, the Active Phosphorus was determined by the addition of Saloid-bound phosphate, Aluminum phosphate, iron phosphate, and calcium phosphate, and total Inorganic P is the summation of all the inorganic forms of P. Total Phosphorus (Total P) in Soil was estimated by using Murphy-Riley solution and 5M NaOH and the intensity of yellow color was read at 730 nm in a spectrophotometer, organic P was calculated from the difference between total phosphorus and total mineral P, and the uptake of phosphorus was computed from the data on P concentration and dry matter yield.
 Results: The release and fixation pattern of different forms of phosphorus, its uptake, and the economic yield of green gram were significantly affected by the application of rock phosphate singly or combination with PSB and lime. Comparing among the different treatments, significantly higher accumulation of available Phosphorus, Phosphorus uptake, and economic yield were recorded in soil treated with Rock phosphate in combination with Phosphocare, Bacillus megatherium, and lime which is at par with treatment with Rock phosphate in combination with Bacillus megatherium and lime.
 Conclusion: The investigation revealed that the release and fixation pattern of different forms of phosphorus, its uptake, and the yield of green gram are significantly affected by the application of RP singly or combination with PSB and lime.

Availability of phosphorus in Ultisols by applying compost and phosphate rock

Ultisols are the largest order in Indonesia among other acid soils, namely around 41,919 million ha, with the problem of insufficient P availability in soil for plant growth, requiring special treatment to increase available P in the soil. This study aims to examine the effect of compost and rock phosphate in increasing the availability of P in Ultisols. The research was conducted in April–May 2016 at the Laboratory of Chemistry and Soil Fertility, University of Hasanuddin, Makassar. The study used a randomized block design and was carried out by incubating straw compost, gamal leaves, cow dung and rock phosphate in Ultisol soil with a soil weight of 300 g. The research results show that 15th day of incubation showed the highest available P of 12.97 ppm with a pH of 5.15 in the KJ575%+KS525%+BF treatment, while on the 30th day of incubation the available P increased 17.45 ppm in the rock phosphate treatment with a pH of 5.58. The application of rock phosphate and SP36 reduced Al-P, Fe-P, and Ca-P, while the application of organic matter, in this case compost, did not reduce Al-P, Fe-P, and Ca-P.

Does phosphogypsum addition affect phosphate rock dissolution in acid soils?

The direct application of phosphate rock (PR) has been found suitable for acidic soils. Still, efforts are needed to improve its reactivity to match grassland P demand. This research aimed to investigate changes in the dissolution of two Moroccan sedimentary PRs (Ben Guerir and Khouribga) in response to four rates of phosphogypsum (PG)—a by-product of the phosphate fertilizer industry. We conducted a 60-day incubation study using two acid soils from New Zealand. The soils were treated with PRs at 100 mgP kg−1 of soil either alone or combined with PG, which was applied at 0, 1, 3 and 9 t ha−1 (approximately the equivalent of 0, 0.9, 2.7, and 8.1 g of PG kg−1 of soil, respectively). The dissolution rates were determined from the differences in residual calcium (Ca) extracted with 1 M HCl. Soil pH, Olsen P, exchangeable aluminium (Al) and Ca and Ca saturation were analyzed at the end of the experiment. Phosphate rocks and PG’s physicochemical properties were characterized. Phosphogypsum addition increased Olsen P by 34% and 59% at 9 t ha−1 compared to 0 t ha−1 in Molesworth and Lindis Peaks soils, respectively. However, PG did not affect the dissolution of PRs in the different of soil types. Khouribga PR was more reactive than Ben Guerir PR, especially in the Molesworth soil where soil pH and base saturation were lower and P retention was higher compared to Lindis Peaks soil. Particle size distribution was the key factor that contributed to the observed greater reactivity of the Khouribga PR. Both PRs showed dissolution rates >50%, suggesting their suitability for direct application on acid soils. Being an important source of sulphur and some P, PG if combined with PR, can promote and complement PR’s direct use as fertilizer on acid soils. Moreover, the development of new fertilizer products by combining these two materials should be encouraged.

Effect of Application of Rock Phosphate with Amendments on Maize Plants Grown on Sandy and Clayey Soils

Effect of Application of Rock Phosphate with Amendments on Maize Plants Grown on Sandy and Clayey Soils

Mycorrhizal Fungi and Rock Phosphate Application to Mitigate Soil Salt Stress and Its Effect on Productivity of ‘Picual’ Olives and ‘Wonderful’ Pomegranates

Mycorrhizal Fungi and Rock Phosphate Application to Mitigate Soil Salt Stress and Its Effect on Productivity of ‘Picual’ Olives and ‘Wonderful’ Pomegranates

Problems, Management, and Prospects of Acid Sulphate Soils in the Ganges Delta

Soil is a finite natural resource and is indispensable for human civilization because it is the medium for food production for the biosphere. Continued soil degradation is a forerunner of catastrophe for the living world. The protection of healthy soils and the restoration of problem soils are strongly needed in the current agricultural scenario as competition for urbanization and other human needs for land resources limits the scope for the further availability of land for agriculture. Naturally occurring degraded soils, such as acid sulphate soils, can be restored with scientific interventions and advanced management strategies. The Ganges Delta is a densely populated region, where the inhabitants’ major livelihood is agriculture. Soil acidity and salinity restrict crop performance in this coastal region, particularly the acid sulphate soils (ASSs) posing a risk to agriculture. ASSs are developed from land-use changes from mangrove forest to agricultural land in this region. There is no systematic study on these soil types covering Bangladesh and India. This paper unfolds several aspects related to the characteristics, problems, and detailed management strategies of ASSs relevant to the Gangetic Delta region where these soils continue to be used for intensive agriculture to meet the livelihood needs. Crop yields are very poor in the unmanaged ASSs due to a very low soil pH (<3.5), hampering the growth and development of crops due to nutrient deficiencies and/or toxicities, coupled with soil salinity. There is toxicity of water-soluble Fe, Al, and Mn. The phosphorus nutrition of crops in these soils is affected owing to a high soil P fixation capacity. A deficiency of micronutrients, such as Zn and Cu, was also observed; however, K availability is variable in the soil. The soil acidity is a general problem throughout the soil profile; however, extreme acidity (pH < 3.5) in particular soil horizons is a typical soil characteristic, which creates problems for its efficient management. Specific operations, such as the selective use of soil layers with good properties for crop root growth, major and minor nutrient applications, and soil amendments, including green manuring, application of biofertilizers, and soil microbes, are gradually improving the properties of these soils and bringing back the potential for good crop production. Scientific water/drainage management is needed to gain an agronomic advantage. Evidence of increased crop yields in these soils observed from green manuring, lime, basic slag, and rock phosphate application are presented.

Improving Upland Acid Soil Properties And Increasing Maize Yield By Phosphate Rock Application With Organic Acids

Problems encountered in the management of upland acid soils, besides soil pH, are also low in phosphorus (P) content and less available to plants. The addition of organic acids (OAs) to the direct application of phosphate rock (PR) has not been widely studied yet and is expected to improve upland acid soil properties. The research aims to determine the effect of adding OAs on the direct application of PR to improve upland acid soil and increase maize yield. It was a greenhouse experiment using a randomized complete design in a factorial arrangement with three replications. The treatments consisted of four types of OA (citric, humic, succinic, and oxalic acid) and five OA concentration levels (0, 25, 50, 100, and 200 ppm). The hybrid maize (Zea mays L) was used as the test crop. The parameters observed were soil properties (pH, exchangeable H (H+), exchangeable Al (Al3+), exchangeable Ca (Ca2+), cation exchange capacity (CEC), available P (as P-Bray1)) and maize growth (plant heights and yield). The results show that the types of OA treatments had no significant effect on soil properties and maize yield; in contrast, the concentrations of OA levels were able to improve soil properties as indicated by a significant effect on pH, H+, Al3+, Ca2+, CEC, available P, and increased maize yield. An increase in soil pH due to the addition of OAs to the direct application of PR could increase Ca2+ and CEC and decrease Al3+ and H+, while increasing available P for plants. Although not significantly different, oxalic acid was able to improve the observed soil properties and maize yield, followed by citric, humic, and succinic acids. The maximum OA concentration was 126.9 ppm. We can say that the main finding of this research is that oxalic, citric, humic, and succinic acids at a concentration of 126 ppm can be applied to phosphate rock. In Indonesia, humic acid has been widely applied by farmers because it is easy to obtain. Therefore, it can be applied to phosphate rock.

Enhancement Effect of Cassava Starch Manufacturing Wastes on Availability and Fate of P from Thai Phosphate Rocks in Sandy Typic Paleusults: An Incubation Study

ABSTRACT Direct application of phosphate rock (PR) can be an alternative to phosphorus (P) fertilizer in highly weathered tropical soils, but the low solubility of PR obstructs its use. The use of cassava peel (CP) and cassava starch waste (CSW) to enhance two Thai PRs (Kamphaeng Phet, KP-PR; 20.3% P2O5 and Lamphun, LP-PR; 14.7% P2O5) was investigated for P availability in two sandy Typic Paleusults in laboratory. Both PRs had low reactivity but similar dissolution behavior as most P dissolved in 2% formic acid (22.2% and 19.0%, respectively, of total P2O5). The CP promoted better PR solubility than did the CSW, resulting in significantly more available P in the soils but P majorly occurred in moderately labile and chemically relatively stable fractions. The labile fraction was still lower than other forms of soil P, especially NaHCO3-Po, but both wastes, especially CP, increased NaHCO3-Pi and -Po to some extent while the soluble Pi (NH4Cl-Pi) became more soluble after 4 months. The relative distributions of the Pi and Po fractions varied over the incubation period with no definite trends detected, but the PR and wastes were correlated variably in all P fractions.

Influence of Biochar, Rock Phosphate, and Urea Nitrogen Fertilizer on Growth and Yield of Cucumber (Cucumis sativus) Grown in Standoff, Southern Alberta Greenhouse

Two trials were performed in greenhouse Standoff, Southern Alberta to investigate urea, rock phosphate, and biochar soil amendment on cucumber crops. The objective of the study was to confirm the effectiveness of rock phosphate and biochar with urea on greenhouse cucumber production. Two experiments were conducted in the Summer of 2020 and 2021 cropping seasons. The treatments applied in 2020 were the varying application of rock phosphate at 0 for control, 50 kg P ha-1 and 100 kg P ha-1 for phosphorus, and urea at 60 kg N ha-1 and 90 kg N ha-1 for nitrogen with their combinations N60 + P50, N90 + P100. In the 2021 cropping season, treatments applied were varying levels of Biochar (C) applied at a rate of 25 kg ha-1 (LC), 50 kg ha-1 (MC), and 100 kg ha-1 HC for Low, Medium, and High level, respectively, Urea (N) was applied at 30 kg N ha-1 and 60 kg N ha-1 (Low N and High N level, respectively) while rock phosphate (P) was applied at 25 kg P ha-1 and 50 kg P ha-1 (Low P and High P level, respectively) with their combinations. The seven treatments for each cropping season were replicated three times resulting in twenty-one experimental pots. The agronomical parameters data collected were subjected to one-way univariate analysis of variance using Duncan’s Multiple Range Test at 5% to separate the treatment means. The results of the experiment showed that High P and Low N treated pots influenced the growth of cucumber crop at 122 days after sowing (DAS) while High N, Low N, and Low N + Low P jointly favored the highest number of cucumbers on the vines than other treated pots at 82 DAS during the 2020 cropping season. However, all the treatments supported cucumber vine length except control and High P at 96 DAS while Low P + MC, High P, and High N+ P produced more fruits than control, High N and Low N + P + HC treatments at 96 DAS during the 2021 cropping season. It was observed that the addition of biochar in the 2021 cropping season influenced the growth and yield of cucumber when compared performance of cucumber crops in two growing seasons. This experiment advocates the use of biochar soil amendment in cucumber production.

PERTUMBUHAN DAN PRODUKSI KEDELAI AKIBAT INOKULASI Rhizobium sp. DAN BAKTERI PELARUT FOSFAT TAHAN SALIN SERTA BATUAN FOSFAT DI TANAH SALIN

<p>The purpose of this study was to examine the effect of <em>Rhizobium sp.</em> and phosphate solubilizing bacteria saline-resistant and the application of phosphate rock to the growth and production of soybean plants in saline soils. The study was carried out using a 3 x 4 factorial design on the basis of a Completely Randomized Design with 3 replications. The first factor is the treatment of <em>Rhizobium sp.</em> and phosphate solubilizing bacteria saline-resistant (CFU 109 cells/g) at 4 levels, namely F0 : 0 mg/pot, F1 : 10 mg/pot, F2 : 20 mg/pot, and F3 : 30 mg/pot. The second factor is the doses of phosphate rock with 3 levels, namely B0: 0 kg/ha, B1: 50 kg/ha, and B2: 100 kg/ha. The results showed that the inoculation treatment of <em>Rhizobium sp.</em> and phosphate solubilizing bacteria saline-resistant were not significantly different on the N uptake parameters of seeds. Treatment with different doses of rock phosphate had no significant effect on all parameters. There was no interaction between <em>Rhizobium sp.</em> and phosphate solubilizing bacteria saline-resistant with a dose of rock phosphate on all observed parameters. Inoculation of <em>Rhizobium sp.</em> and phosphate solubilizing bacteria saline-resistant and rock phosphate have not been able to significantly increase the growth and production of soybean varieties Anjasmoro in highly saline growing media with EC 6,26 dS/m, although there is a tendency to increase soybean production.</p>

A phospho-compost biological-based approach increases phosphate rock agronomic efficiency in faba bean as compared to chemical and physical treatments.

Under arid and semi-arid conditions, direct application of phosphate rock (PR) as a source of phosphorus (P) for crop production is likely influenced by agricultural practices and soil properties. Different approaches could be used to improve the agronomic efficiency of low-grade PR over a wider range of soils and crops. In this study, biological, physical, and chemical treatments of low-grade Moroccan PR were investigated and compared through agronomic trials on faba bean grown under alkaline soil conditions. The physical treatment was based on blending PR with triple superphosphate (TSP) at 75:25 and 50:50 ratios, the biological treatments involved co-application of PR with compost at 50:50 ratio and phospho-compost elaborated from PR (20%), sewage sludge (46%), and wheat residues (34%), while the chemical treatment was obtained by a 30% acidulation of PR by phosphoric acid. Control treatments consisting of zero P application (control), PR alone, and TSP alone were considered to assess the effectiveness of the abovementioned techniques to improve PR agronomic efficiency. A pot experiment was conducted in sandy soil (Jorf Lasfar, central Morocco) for 60 days in a completely randomized design considering eight treatments. All treatments, except the control, were amended with 52 mg kg-1 of P from different PR-based fertilizers before sowing. At the flowering stage (60-day-old plants), results indicated that all PR treatments significantly improved plant growth, root nodulation, and nutrient uptake compared to the control. The relative agronomic efficiency of pretreated PR was significantly higher with phospho-compost treatment (86%) than the partially acidulated PR (78%) or the PR/TSP blend 50:50 (64%). Likewise, P uptake, P use efficiency, number of root nodules, and N uptake all were improved under PR treatments. Our finding revealed that the biological technique based on phospho-compost yielded better compared to chemical and physical treatments.

Carbon Dioxide Emission, Soil Properties, Intercropping of Cucumber-Tomato and Carrot-Cabbage Crops Performance Affected by Application of Biochar, Urea, and Rock Phosphate

Application of biochar soil amendment is a good practice to store carbon dioxide (CO2) in the soil to mitigate climate change, rock phosphate and urea fertilizer increase soil fertility to enhance food security. This greenhouse experiment aimed to evaluate the effect of biochar, rock phosphate, and urea on cucumber-tomato intercrop and evaluate the carbon dioxide (CO2) emission in the soil grown with cabbage-carrot intercrop. The first experiment was carried out using varying levels of rock phosphate (25, 50 kg ha-1), biochar (25, 50, 100 kg ha-1) and urea (30, 60 kg ha-1) and control with no fertilizer application. The treatment combinations were replicated three times resulting in twenty-one experimental pots. The second experiment involved the application of biochar at different levels of application (25, 50, 100 kg ha-1) and control with no fertilizer application, all the pots across the experiment received an equal application of urea at a rate of 30 kg ha-1 and rock phosphate at a rate of 25 kg ha-1 replicated three times resulting in 12 experimental pots for cabbage-carrot intercrop while 15 pots with an extra biochar application of 120 kg ha-1 for cabbage only. Results showed that High nitrogen plus High phosphorus (N + P) including Low phosphorus plus Medium biochar (Low P + MC), Low nitrogen plus Low phosphorus plus High biochar (Low N + Low P + HC), and Low nitrogen plus Low biochar (Low N + Low C) supported the height of cucumber while Low nitrogen plus Low biochar (Low N + Low C) and High nitrogen (High N) positively influenced height of tomato. There was no significant difference in the number of cucumber fruits produced since the control and high N treatments significantly got the same number of cucumber fruit. In contrast, Low nitrogen plus Low biochar (Low N + LC) treated to tomato crop got the highest number of tomato fruits. In the second experiment, the Highest biochar including High biochar and Low C (Low biochar), favoured cabbage’s height while no significant effort in the treatments to support carrot height. It was estimated that the High C treatment gave the highest carbon dioxide emission while the Highest C treatment stored carbon dioxide in the soil.