Water, Soil and Nutrients Losses by Runoff at Hillslope Scale in Agricultural and Pasture Production in Southern Brazil

Abstract

Agricultural activity, if not well managed, is an important source of water pollution mainly by surface runoff. The aim of this study was to evaluate losses of water, soil and soluble nutrient (phosphorus, nitrogen and carbon) via runoff in large plots (hillslope from 3,000 to 11,000 m2) at slope of 4 to 5% in annual crops (corn and sunflower) and pasture systems under no-tillage and no-pesticides. The study was carried out at the Canguiri Experimental Farm of the Federal University of Paraná, Southern Brazil, in soil classified as Ferralsol in three systems (crop, pasture and crop-pasture). Soil physical and chemical attributes as well as topographic indices and soil cover were investigated to evaluate the possible impacts of these variables on losses. The runoff was measured after each rainfall event from November 2014 to October 2015. Runoff samples were taken to analyse sediment and nutrients. All systems had low water, soil and nutrients losses compared to no conservative agricultural systems. Higher losses occurred in the annual crops system and were influenced by soil cover, with an annual runoff coefficient of 0.62% (7 mm of water loss) and an annual soil loss of 2.6 kg ha-1. The seasonality (winter/summer) did not influence soil, water and nutrient losses.

Soil Structural Quality and Relationships With Root Properties in Single and Integrated Farming Systems

“…This soils were associated with lower levels of soil organic carbon, evidencing the importance of carbon inputs from roots into the soil. Coblinski et al (2019) studied the same experimental area, and showed that soil bulk density, porosity, soil water availability, as well SOC influence soil structural quality. According to Colombi et al (2018), interactions between root architecture, plant water uptake, soil moisture, and soil penetration resistance are little studied.…”

Investigating Near-Surface Hydrologic Connectivity in a Grass-Covered Inter-Row Area of a Hillslope Vineyard Using Field Monitoring and Numerical Simulations

“…Surface runoff in hillslope soils has significant impacts on sediment yield, nutrient transport, and consequently water quality [8,9]. In vineyards, heavy rainfall often increases and accelerates several negative impacts, including soil aggregate breakdown, soil sealing, nutrient leaching, excessive vine vegetative growth, and fruit disease [10].…”

Impacts of soil use and management on water quality in agricultural watersheds in Southern Brazil

“…Most studies of water, sediment and nutrient losses in Brazil with soil tillage and management systems have been done in small plots with simulated or natural rainfall (Bertol et al, 2011; Bertol, Rizzi, Bertol, & Roloff, 2007; Denardin, Kochhann, Faganello, Sattler, & Manhago, 2008; Gebler, Bertol, Ramos, Louzada, & Miquelluti, 2012; Guadagnin, Bertol, Cassol, & Amaral, 2005; Silva & De Maria, 2011). Studies at greater scale are needed and field experiments with large plots in Brazil have been increased recently (Coblinski et al, 2019; Deuschle et al, 2019; Londero et al, 2018; Merten et al, 2015; Ramos et al, 2014). Losses of soil, water and agrochemicals in a watershed cannot be estimated by the sum of results from individual fields, even from large plots (Ding et al, 2016; Raclot et al, 2009; van de Giesen, Stomph, & de Ridder, 2005) so studies at watershed scale following the real field condition are essential to assess water quality (Capoane, Tiecher, Schaefer, Ciotti, & dos Santos, 2015; Gafur, Jensen, Borggaard, & Petersen, 2003; Martínez‐Casasnovas, Ramos, & Benites, 2016; Niu et al, 2015; Nu‐Fang, Zhi‐Hua, Lu, & Cheng, 2011; Shi et al, 2012; Shore et al, 2014; Shore et al, 2017) as well as to calibrate empirical mathematical models (Durães, de Mello, & Naghettini, 2011; Raclot et al, 2009; Shi et al, 2012; Tong & Chen, 2002; van de Giesen et al, 2005).…”