Soil, forage, and weed attributes following tillage in grazed no‐tillage triticale pasture

Abstract

AbstractGrazing annual forages in dryland cropping systems has been used to integrate crop and livestock systems, rejuvenate soils, enhance in‐field nutrient cycling and soil organic carbon (SOC), and increase net returns by eliminating harvest expenses and feed delivery. However, cattle (Bos taurus) could potentially degrade soil physical properties by increasing compaction and reducing water infiltration in no‐tillage (NT) systems. Minimum tillage (MT) may help correct some of these potential soil quality concerns. The objective of this study was to quantify MT effects on soil properties, forage mass, and weeds compared to NT in a grazed winter triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)] annual forage system from 2020 to 2022 near Jetmore, KS. The experiment had two tillage treatments, NT and MT (sweep plow to a depth of 5–13 cm twice during summer fallow), in a grazed continuous winter triticale cropping system. Bulk density was greater in June, pre‐till (1.31 g cm−3), compared to August, post‐till (1.23 g cm−3), across tillage treatments. The mean weight diameter of dry aggregates decreased, and wind‐erodible fraction increased with MT. Across years, the mean weight diameter of water‐stable aggregates was greater with NT compared to MT. The SOC stocks did not differ between tillage practices near the soil surface, but MT increased SOC at the 5‐ to 15‐cm depth. Nitrate (NO3‐N) concentration was 28% higher with MT compared to NT across depths at the August sampling time. Soil pH was slightly lower in NT (5.81) compared to MT (5.94). Penetration resistance was high due to frequently dry soil conditions, but there were no differences between tillage systems. Early‐season forage biomass was greater in MT compared to NT in one out of two seasons. Our findings suggest that MT could be used to mitigate adverse effects of grazing on soil bulk density in NT systems but could cause short‐term decreases in dry and wet aggregate stability and increased wind‐erodible fraction.