Land‐use effects on soil macro‐ and micronutrient status in tropical lowland zone of Bolivia

Abstract

The present study investigated macro‐ and micronutrient status in the soils under the native forest (NF), cropland (CL) and rangeland over 27 years in Colonia Okinawa, Santa Cruz, Bolivia, in order to assess the effect of land use on soil fertility in the region. The C, N and P pools in the soil of CL were less by 60, 57 and 27% as compared to NF, respectively. The rangeland with Panicum maximum (RG) showed almost similar values of C, N and P pools to CL, while the values in the rangeland with Paspalum notatum (RB) were relatively closer to NF. Mehlich‐3 extractable P, Ca and Mg considerably declined in CL, RG and RB, but an inverse trend was observed in Mehlich‐3 extractable K probably due to the stimulation of weathering of illite in the soil. Mehlich‐3 extractable Mn, Fe and Cu were tended to increase in RG and RB, which suggested possible accumulation of these metals because of the manure deposited by grazing cattle on the rangelands. Besides C, N and P pools, the values of Mehlich‐3 extractable K, Mn, Fe and Zn were less in RG than RB because of greater exploitation of these nutrients in RG than RB. There was a significant correlation between C, N, P, Ca, Mg and Zn suggesting that the dynamics of these components could be associated with the organic matter in the soil. The findings of this study clarified the soil chemical degradation in the cropland and rangeland. However, the magnitude of the land chemical deterioration under the rangeland was highly variable depending on the grass species.

Can the African food supply model learn from the Asian food supply model? Quantification with statistical methods

“…While this is argued as being good for the yields, these studies also note that with a lack of functional riparian zones, there is a high level of risk for the degradation of soils and water systems in the long run (Lindell et al 2010a, b, c). These views have been supported by studies on chemical fertilizers that have degraded soils in Bolivia and West Amazonian (Abe et al 2007;Araujo et al 2004).…”

Effects of land‐use change on chemical composition of soil organic matter in tropical lowland Bolivia

“…To the same extent, the total N content of the soils changed by –59%, –41% and –14% in the order of CL, RG and RB, respectively. These declines in C and N were well associated with phytoavailable (Mehlich‐3 extractable) nutrients such as Ca, Mg, P and Zn (Abe et al . 2007).…”

“…2003). In this region, Abe et al . (2007) reported a significant decline in C, N and P levels and Mehlich‐3 extractable P, Ca and Mg in the soils after conversion of semideciduous forests to agricultural lands.…”

“…A typical case of soil degradation has been documented in Colonia Okinawa, south‐east Bolivia (Abe et al . 2007) where the large‐scale mechanized farming system and extensive livestock (mainly cattle) production has been developed without the use of fertilizers since Japanese immigrants started to settle in 1956 (Takata et al .…”

Comparison of Physicochemical Properties of Soils under Contrasting Land Use Systems in Southwestern Nigeria

“…Land clearing and subsequent crop cultivation often results in the loss of organic C in the soil in the tropics (Abe et al 2007c, 2009a, Detwiler 1986, Don et al 2011 because of rapid decomposition of organic matter under the tropical climate (Jenkinson & Ayanaba 1977). In contrast, the soils of the forest had approximately 10 mg kg -1 higher organic C content than cropland (Thomas et al 1992).…”