Resumo -O objetivo deste trabalho foi identificar erosões em bacia hidrográfica e avaliar práticas conservacionistas de manejo do solo para a recuperação da degradação, por meio do monitoramento de indicadores de qualidade de água e por imagens de satélites. O monitoramento, por um período de 14 anos, foi realizado em 14.076 ha da bacia do Rio do Peixe, selecionada por ser a mais degradada do Estado de São Paulo, que abrangem 176 propriedades agrícolas exploradas basicamente com pastagens e café. Destas, 82 apresentaram algum tipo de erosão, além de 12 trechos de estradas municipais que contribuíram com processos erosivos nas áreas agrícolas. As práticas de manejo conservacionista do solo e da água implantadas em 86 propriedades da bacia permitem alteração positiva da paisagem e de rendimento da atividade agrícola, mudança comprovada pelas imagens aéreas e pelos indicadores de qualidade da água. A metodologia apresentada de monitoramento e de reabilitação agroambiental é viável e pode contribuir para o manejo e o monitoramento de microbacias.Termos para indexação: assoreamento, bacia hidrográfica, cobertura vegetal, conservação do solo, erosão hídrica, imagem aérea. Agri-environmental diagnostic and rehabilitation in a stretch of a hydrographic basin assessed by remote sensing and water turbidityAbstract -The objective of this work was to diagnose erosions in a hydrographic basin and to evaluate conservationist soil management practices for degradation recovery, by monitoring water quality indicators and satellite images. Monitoring was done for 14 years in 14,076 ha of the basin of Rio do Peixe, which was selected for being the most degraded one in the state of São Paulo, Brazil, circumscribing 176 farms, basically explored with pastures and coffee. Out of these farms, 82 showed some kind of erosion, besides 12 stretches of municipal roads that contributed to the erosion processes in the agricultural areas. The conservationist soil and water management practices established in 86 of the farms at the basin allow positive changes on the landscape and on the income from agricultural activity, which were shown in the aerial photos and by the water quality indicators. The adopted monitoring and agri-environmental rehabilitation methodologies are viable and may contribute to managing and monitoring microbasins.

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This study aimed to evaluate the works undertaken on the Rio do Peixe watershed by the Coordination of Agricultural Defense (CDA) over 12 years, where conservationist agriculture practices have been used since 2007 to promote the recovery of degraded areas, the reduction of erosion and the improvement of water quality. In addition, we evaluated the performance of innovative diagnostic strategies used to identify erosion spots in the river basin. The effective supervision of large farmland areas is a common problem that requires the development of cost-effective tools while keeping a close interaction with stakeholders. From 2007 to 2017, 176 properties (23,103 ha) were inspected and notified to fulfill the soil conservation laws, using the Conventional CDA methodology (i.e., field assessment by an agronomist). In the Marília sector, the Innovative CDA Methodology (with remote sensing) was used, enabling the audit of 52 properties covering 27,775 ha in 2 years. Each landowner was requested to submit technical projects using conservationist practices to be implemented under CDA guidelines.Methods included vegetation cover and crop rotation (control of laminar erosion) and implementation of agricultural terraces, bypass channels, and containment basins (management of gullies erosion). The activities carried out promoted a shift from conventional agriculture, which was impacting soil fertility and water quality, towards conservation agriculture. Degraded pastures were converted into annual cropping areas using No-Tillage (zero tillage) farming techniques. Other pastures were recovered, through Integrated Crop-Livestock Systems, increasing its stocking rate. The undertaken activities were labor-intensive but beneficial for farmers and for the quality of waterbodies.

The overarching goal of this study is to test innovative monitoring strategies for agricultural properties at watershed towards effectively locating erosions and correcting them, through the implementation of changes in soil management strategies. The purpose is to recover and restore degraded areas, and promote conservation agriculture. The results are, assessed by remote sensing and water quality indicators. In 2019, twelve years were completed of inspection/monitoring at Rio do Peixe watershed.From 2007 to 2017, 14,076 ha, were inspected at Vera Cruz sector, using the Conventional CDA methodology, with 94 properties having been notified. In Ocauçu, a total of 82 properties were notified, in a total surface of 9,027 ha. In Marília, the Innovative CDA Methodology was used, which allowed the inspection and rehabilitation of 52 properties, across 27,775 ha, from 2017 to 2018. After the notifications, the owners presented the conservationist technical projects for each property, which were, implemented using conservation practices, such as: improvement of vegetation cover and crop rotation, to control laminar erosion; and agricultural terracing, divergent channels and containment basin, to control gullies erosions. This work promoted a transformation from degrading agriculture to conservation agriculture, with degraded pastures having been altered into agricultural areas, with the implementation of the No-tillage. Pastures were recovered through the Integrated Crop-Livestock System, and occupancy rate was increased by 31%. This work has demonstrated to benefit Watershed farmers, by increasing their productivity and consequently the profit, as well as the local communities, improving the quality of water that supplies the region.

This a preprint and has not been peer reviewed. Data may be preliminary.