Inter-row soil management affecting the soil-plant-water system in vineyard

The objectives of the study was to 1) investigate soil-plant-water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed vineyards, and 2) modeling changes in the SWC due to differences in soil physical parameters among slope positions and management methods. The study explored the impact of three different soil management practices on grapevine growth and soil health in vineyards: tilled (T), cover crops (CC), and perennial grass (NT) inter-rows. Data was collected for 2022 and 2023. At each study slopes, we had two measurement points along a slope section. To continuously monitor soil water and temperature conditions, sensors were strategically positioned at two depths of 15 cm and 40 cm below the soil surface along the slopes, both at the upper and lower points of the vineyard, while topsoil SWC was measured bi-weekly. Normalized Difference Vegetation Index (NDVI) and Photochemical Reflectance Index (PRI) sensors were used to measure leaf reflectance, while handheld instruments were used to measure additional NDVI and leaf Chlorophyll contents (SPAD). For the hydrological modeling we used SWAP (Soil-Water-Atmosphere-Plant), where the rswap R-package was used for calibration (2020 15 and 40cm data), validation (2021 15 and 40cm data), and statistical evaluation.

In 2022, all three slopes showed a significantly higher SWC content for the higher points compared to the lower, while in 2023 the grassed slope upper point showed higher SWC (0.18 vs 0.15%). The highest NDVI values were measured for the cover cropped vineyard site (0.68). However, we found no significant differences among NDVI values based on inter-row management or slope position, only the grassed inter-row vineyard had differences in the NDVI values at the lower and upper points (p=0.034). The highest leaf chlorophyll contents were measured for the cover cropped vineyard site (305). Most of the leaf Chlorophyll values were not significantly different among slope positions. Using the SWAP model, data from the cover cropped inter-row vineyard was used for calibration and validation. We found good model fitting (NSE > 0.52; d_daily > 0.81). Reduced-tillage (RT) and drought tolerant plant (DTP) management scenarios were run to simulate SWC changes over time. Preliminary data shows that DTP significantly reduced, while RT did not significantly affect our site’s SWC.

Acknowledgments: This material is based upon work supported by the Hungarian National Research Fund (OTKA/NKFI) project OTKA FK-131792. The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.