  Citation: Williams, W.J.; Schmidt, S.; Zaady, E.; Alchin, B.; Myint Swe, T.; Williams, S.; Dooley, M.; Penfold, G.; O’Reagain, P.; Bushell, J.; et al. Resting Subtropical Grasslands from Grazing in the Wet Season Boosts Biocrust Hotspots to Improve Soil Health. Agronomy 2022, 12, 62. https://doi.org/10.3390/ agronomy12010062 Academic Editor: Shan Lin Received: 11 November 2021 Accepted: 21 December 2021 Published: 28 December 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). agronomy Article Resting Subtropical Grasslands from Grazing in the Wet Season Boosts Biocrust Hotspots to Improve Soil Health Wendy J. Williams 1, * , Susanne Schmidt 1 , Eli Zaady 2 , Bruce Alchin 1 , Than Myint Swe 1 , Stephen Williams 1 , Madeline Dooley 1 , Grace Penfold 1 , Peter O’Reagain 3 , John Bushell 3 , Robyn Cowley 4 , Colin Driscoll 1 and Nicole Robinson 1 1 NUE Lab, School of Agriculture and Food Sciences, The University of Queensland, St Lucia, QLD 4074, Australia; susanne.schmidt@uq.edu.au (S.S.); b.alchin@uq.edu.au (B.A.); t.myintswe@uq.net.au (T.M.S.); u1077155@umail.usq.edu.au (S.W.); madeline.dooley@uq.net.au (M.D.); g.penfold@uq.net.au (G.P.); c.driscoll@uq.edu.au (C.D.); nicole.robinson@uq.edu.au (N.R.) 2 Department of Natural Resources, Institute of Plant Sciences, Agricultural Research Organization Gilat Research Center, Negev 8531100, Israel; zaadye@volcani.agri.gov.il 3 Queensland Department of Agriculture and Fisheries, Charters Towers, QLD 4820, Australia; peter.oreagain@daf.qld.gov.au (P.O.); john.bushell@daf.qld.gov.au (J.B.) 4 NT Department of Industry, Tourism and Trade, Darwin, NT 0801, Australia; Robyn.Cowley@nt.gov.au * Correspondence: wendy.williams@uq.edu.au Abstract: Effective grazing management in Australia’s semi-arid rangelands requires monitoring landscape conditions and identifying sustainable and productive practice through understanding the interactions of environmental factors and management of soil health. Challenges include extreme rainfall variability, intensifying drought, and inherently nutrient-poor soils. We investigated the impacts of grazing strategies on landscape function—specifically soil health—as the foundation for productive pastures, integrating the heterogenous nature of grass tussocks and the interspaces that naturally exist in between them. At Wambiana—a long-term research site in north-eastern Australia— we studied two soil types, two stocking rates (high, moderate), and resting land from grazing during wet seasons (rotational spelling). Rotational spelling had the highest biocrust (living soil cover), in interspaces and under grass tussocks. Biocrusts were dominated by cyanobacteria that binds soil particles, reduces erosion, sequesters carbon, fixes nitrogen, and improves soil fertility. Rotational spelling with a moderate stocking rate emerged as best practice at these sites, with adjustment of stocking rates in line with rainfall and soil type recommended. In drought-prone environments, monitoring the presence and integrity of biocrusts connects landscape function and soil health. Biocrusts that protect and enrich the soil will support long-term ecosystem integrity and economic profitability of cattle production in rangelands. Keywords: landscape function; drylands; tropical rangelands; grazing; soil health; biocrusts; drought 1. Introduction Beef cattle grazing is the dominant industry in Australia’s subtropical and tropical savannas and grasslands that cover much of the continent. Vast grazing properties of 10- to 100-thousand hectares require land managers to maintain pasture composition and production [1]. Inherently nutrient-poor soils and highly variable rainfall mainly driven by ENSO (El Niño/La Niña Southern Oscillation) cycles constrain the quantity and quality of forage. Significant economic loss [2] and declines in ecosystem function [3] result from a failure to manage for seasonal rainfall variability and landscape heterogeneity at large spatial scales. Northern Australia’s rangelands, the focus of this study, have a distinct dry season over mild winter months followed by a hot summer wet season (2–6 months) when most pasture growth occurs. Resting the landscape (i.e., temporary cattle removal) during the dry winter months when grasses are dormant is deemed ineffective, while Agronomy 2022, 12, 62. https://doi.org/10.3390/agronomy12010062 https://www.mdpi.com/journal/agronomy