Relationship Among Crop Systems, Soil Cover, and Water Erosion on a Typic Hapludox

Abstract

Several soil conservation practices are used to reduce water erosion and ensure sustainable agriculture. An effective crop management practice is intercropping, in which two or more crops with different architectures and vegetative cycles are grown simultaneously in the same area. We hypothesized that intercropping of corn and jack-bean increases soil cover and reduce soil erosion by water in comparison to monocropping. The objective of this study was to evaluate the effects of different crop systems on soil cover and on soil erosion by water. Soil and water losses from a Typic Hapludox were measured under the following systems: corn cultivation (CO), jack-bean cultivation (JB), intercropping of corn and jack-bean (IC), and bare soil (BS), as a reference for maximum erosion rates. For each crop system, erosion plots with dimensions of 12 × 4 m were set up in the field on a 0.12 m m -1 slope gradient. The experiment was carried out under natural rainfall, over three crop seasons (November to March) from 2011 to 2014. The soil cover index of the systems was monitored during crop growth, and rainfall erosivity for the crop seasons was calculated according to the EI 30 index to interpret soil and water losses. A set of linear mixed models was fitted to relate soil losses to rainfall erosivity, crop systems, and soil cover. The average rainfall erosivity in the study area was 6,132 MJ mm ha -1 h -1 per crop season. The results indicate that water losses are directly related to erosivity and are less influenced by soil cover and cultivation systems than the soil losses. A linear maximum value of the soil cover index was achieved 70 days after sowing. Intercropping exhibited greater soil cover than single crops. Total soil losses from the three seasons display the trend: BS > CO > JB > IC. The best fitted model of the linear mixed models indicates that soil loss responses are strongly correlated with rainfall erosivity and soil cover, which nullified the influence of the crop systems in the model.

Tracing the origin of reservoir sediments using magnetic properties in Southeastern Brazil

“…As soils, sediments and rocks from different locations in a catchment are characterized by different magnetic properties (Cervi, Maher, Poliseli, Souza, & Costa, 2019), and so such a technique can be used on different soil classes. The similarity of Catena A soil clay magnetic susceptibility values to those of the reservoir sediments (Figures 12 and 13) can be indicative of a higher erosion rate in Catena A than Catena B soils, as stated by Lima et al (2018) and A. M. Silva et al (2005), respectively. This finding is explained by the higher water infiltration in Catena B soils, a consequence of the granular structure compared with the blocky structure of Catena A soils, which promotes lower water infiltration and consequently higher runoff (Ferreira, Fernandes, & Curi, 1999).…”

“…The two dominant soils in the catchment are Typic Hapludox and Anionic Acrudox (E. Silva, 2018). Both highly eroded potential (A. M. Silva et al, 2005;Lima et al, 2018) soils were sampled through representative catenas under different land uses: native forest, crop, eucalyptus and native pasture (Table 1). Due to issues with permissions, the soils from catena B were located just outside the watershed boundary.…”

On the evaluation of soil erosion models: Are we doing enough?

“…Table 4 Parameters and operating equations for the revised MMF model. Runoff transport capacity (kg m -2 ) C = product of the C and P factors of the USLE Sources: Morgan (2001Morgan ( , 2005 The model was applied at two set of replicate plots, which were part of an erosion monitoring experiment at the Lavras Federal University, Brazil (Lima et al, 2018) The model application within the GLUE methodology was performed under two different scenarios. For scenario I, all parameters considered uncertain were allowed to vary across the full range of possible values reported in the MMF guidelines, regardless of a strict physical meaning.…”

Land-use change effect on the hydro-dynamic characteristics of soil in the Brazilian semi-arid region

“…Soil use and management impact its physical quality, mainly soil aeration. However, it also makes the soil susceptible to erosion above all for monocultures (Lima et al, 2018). Replacing native vegetation by forage palm crop, due to soil management necessary for cultivation, modifies the physical properties of the soil in ways that can make restoration of native forest impossible (Soares, 2018b).…”