Managing Phosphate Rock to Improve Nutrient Uptake, Phosphorus Use Efficiency, and Carrot Yields

Abstract

The objectives of this study were to assess (a) the efficiency of lemon and pineapple juices and the concentration and time needed to release more than 50% of available phosphorus from phosphate rock (PR), and (b) the effect of different types of PR management on carrot yields, nutrient uptake, and phosphorus use efficiency. Field trials were set up at two sites with humic andosols and orthic acrisols over two seasons in Kenya. In a randomized complete block design, replicated three times, the following treatments were compared: (i) composted dissolved PR in lemon juice; (ii) powdered PR composted; (iii) dissolved PR in lemon juice added to compost; (iv) powdered PR and compost; (v) triple superphosphate and compost; (vi) compost alone; (vii) triple superphosphate and Tithonia diversifolia mulch; with (viii) un-amended soil as a control. Lemon juice was effective in solubilizing PR, releasing 63% of the total phosphorus applied into available phosphorus, compared to 11% for pineapple juice and 6% for water. The combined application of compost and PR dissolved in lemon juice at planting significantly increased phosphorus and potassium uptake, phosphorus use efficiency, and carrot yields that was comparable to the use of triple superphosphate and compost. The study concludes that the dissolution of phosphate rock with lemon juice at a ratio of 1:5 phosphate rock to lemon juice and its combined application (immediately after dissolution) with compost at planting improves nutrient uptake, phosphorus use efficiency, and crop yields. We recommend further studies to explore the possibility of using citrus peels or other acidic organic materials to enhance the solubility of phosphate rock, and to assess their practical feasibility and the economic advantage(s) in the large-scale production of high value crops.

EFICIENCIA DE UN BIOL ELABORADO A PARTIR DE RESIDUOS DE COSECHA EN LA PRODUCCIÓN DEL CACAO (Theobroma cacao L.), CLON TSH 565 EN UNA PLANTACIÓN ORGÁNICA AGROFORESTAL

“…El biol combinado con la enmienda solida muestra ser más eficaz en solubilizar la roca fosfórica para liberar P disponible, presumiblemente al contenido de ácidos orgánicos en el biol y a un mejoramiento en las condiciones del pH del suelo. Sobre esta respuesta Mwangi et al, (2020) explicaron que el 44 % de la solubilización de rocas fue causado por el pH y presencia de ácidos orgánicos, además el biol contiene un 50% de N en formas amoniacales y un 60% de P en forma inorgánica que despueś de su aplicación al suelo es rápidamente asimilado por la planta. Esta mayor transferencia de macro y micronutrientes por el biol en comparación con abonos a base de rocas fue explicada por Lourenzi et al, (2021), además de su contribución a mejorar las cosechas (Bacca et al, 2020).…”

Minjingu phosphate rock solubilization and potential for use of Klebsiella variicola-MdE4 and Klebsiella variicola-MdG1 as biofertilizer for maize production

“…Non-microbial techniques include use of acidifying agents such as lemon and pineapple juices (Mwangi et al, 2020) or buttermilk (Cicek et al, 2020). These approaches are, however, only feasible on small-scale field applications.…”

Effect of basalt rock powder associated with different substrates on the initial development of aroeira seedlings (Myracrodruon urundeuva)

“…The use of rocks to obtain nutritional gains can be done in different ways. For example, Mwangi et al (2020) concluded that the dissolution of phosphate rock with lemon juice and its combined application (immediately after dissolution) with compost at planting improves nutrient uptake, phosphorus use efficiency and crop yields of Daucus carota L. On the other hand, Boroumand et al (2020), working with Nasturtium Research, Society andDevelopment, v. 9, n. 12, e5591210790, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i12.10790 officinale R. Br. and phosphate solubilizing bacteria from rhizospheres, enhanced the soil nitrogen and phosphorus content and the vegetative growth of land cress plants.…”