Variability and correlation of selected soil attributes and maize yield influenced by tillage systems in mountainous agroecosystem

Abstract

Soil and topographic variability severely influence agricultural productivity and food security in a mountainous agroecosystem. Understanding these soil spatial disparities are important to optimize suitable land use planning and adoption of appropriate conservation practices to ensure sustainable agricultural productivity in mountainous regions. A field survey and sampling of 108 elevation sites were conducted to assess spatial dynamics and influence of prevalent tillage systems on selected soil attributes and on reported maize (Zea mays L.) grain yield (MGY) in mountainous valleys of Pakistan. Measured soil properties were effective soil depth (ESD), soil penetration resistance (SPR), soil bulk density (SBD), fraction of rock fragments (FRF), soil organic matter (SOM), and soil water holding capacity (SWHC). Additionally, the influence of three existing tillage systems—integrated tillage (IT), bullock tillage (BT), and tractor tillage (TT)—on soil properties and MGY were assessed. Research results showed that ESD, SPR, SBD, FRF, SOM, SWHC, and MGY varied from 15.0 to 40.0 cm, 180.0 to 278.0 psi, 0.9 to 1.7 g cm⁻³, 13.2% to 43.5%, 0.6% to 2.9%, 10.5% to 35.6%, and 4.1 to 10.2 t ha⁻¹, respectively. Differences between soil parameters were significant among the sampling sites studied. Soil properties were found to be strongly associated with each other and with the MGY and were grouped through Pearson correlation, principal component analysis, and heatmap. Moreover, significant variation of soil properties was noted due to the tillage systems adopted by the farmers. The ESD (26.8 cm), SOM (1.4%), SWHC (16.9%), and MGY (7.8 t ha⁻¹) were the highest under IT while the SPR (262.8 psi), SBD (1.6 g cm⁻³), and FRF (38.0%) were the greatest with TT compared to the other tillage systems. Findings of this study are imperative for agriculturists, soil managers, land use planners, and policy makers to identify and implement suitable interventions for sustainable use of agricultural lands to bring economic produce while conserving the mountainous agroecosystem and its resources on sustainable basis.