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Abstract

Ecuador is the most important exporter of canned peach palm, however, to date ideal soil fertility characteristics for peach palm growers remain unknown. The aim of this research was to determine optimal levels of soil nutrients for the cultivation of peach palm, specifically with regards to soil cation exchange capacity in order to obtain higher yields. We worked with 20 farmsteads and their soils from the province of Santo Domingo de los Tsáchilas during the second half of 2014. Fields were evaluated based on a relative yield and extractable (modified Olsen) nutrient contents in each soil were determined using regression modeling to determine critical levels of each nutrient and specifically to determine the ideal soil cation exchange capacity under peach palm cultivation. Our analysis established critical levels of soil pH (6.3); OM 6.5%; P 12.3 mg.dm-3; K 0.67 cmol.dm-3 K; Ca 5.1 cmol.dm-3 ; Mg 0.97 cmol.dm-3; and S 7.5 mg.dm-3. The ideal Ca: Mg: K soil cation exchange capacity was determined to be 76:14:10.

Suitability evaluation of some peri-urban soils for rainfed arable crop production in Lagos State, Southwestern Nigeria

“…This could be as a result of leaching due to high intensity of rainfall and the parent materials that are inherently poor in weatherable cation-yielding minerals in addition to the preponderance of low activity clays of the soils. Calcium levels are generally below the minimum requirement of 3.8 cmol/kg in almost all the soils (Quezada-Crespo et al, 2017). The micro-nutrients (Fe and Zn) are at sufficiency level only at the top soil.…”

“…The chemical properties revealed that a available P is generally deficient as none of the pedons contains the required critical level of 15 mg/kg (Fernandes and Soratto, 2012) for sustainable arable cropping. The soils are also low in potassium, with values of K ranging from 0.13 cmol/kg at the surface in Dodokindo Series to 0.31 cmol/kg at both Atan and Pakoto Series' which are just within the lower limits of the critical level of 0.2 -2.6 cmol/kg (Quezada-Crespo et al 2017). Effective Cation Exchange Capacity is above the critical value of 5.0 cmol/kg observed by Quezada-Crespo et al (2017) in Dodokindo and Owode Series but are lower in the other soil types.…”

“…The soils are also low in potassium, with values of K ranging from 0.13 cmol/kg at the surface in Dodokindo Series to 0.31 cmol/kg at both Atan and Pakoto Series' which are just within the lower limits of the critical level of 0.2 -2.6 cmol/kg (Quezada-Crespo et al 2017). Effective Cation Exchange Capacity is above the critical value of 5.0 cmol/kg observed by Quezada-Crespo et al (2017) in Dodokindo and Owode Series but are lower in the other soil types. This could be as a result of leaching due to high intensity of rainfall and the parent materials that are inherently poor in weatherable cation-yielding minerals in addition to the preponderance of low activity clays of the soils.…”

Characterization and agricultural potentials of some pedons derived from sand stone parent rock near Abeokuta, Southwestern Nigeria

“…The ECEC values of the soils are above the minimum standard of 4.0 cmol/kg in all portions of the land area owing principally Orimoloye et al 91 to Calcium levels that are generally higher than the minimum requirement of 3.8 cmol/kg in all the soils. These according to Crespo et al (2017) are dependent on such parameters as pH and organic matter content of the soils. The organic carbon levels of the soils are low ranging from 1.1 to 2.68 g/kg which is far below the critical level of 30 g/kg proposed by ISRIC (1995).…”

“…Their critical values are 20 to 25, 1.2 to 2.0 and 3.0 to 3.45 mg/kg, respectively. The iron (Fe) content of the soils are however very high, far above the critical value of 161 mg/kg (Feiziasl et al, 2009;Crespo et al, 2017). Those nutrient elements that are below the critical levels need be supplied through deliberate fertilizer application to build up their levels in the soil.…”