Quantifying Soil Compaction in Persimmon Orchards Using ISUM (Improved Stock Unearthing Method) and Core Sampling Methods

Ehsan Moradi,Artemi Cerdà,Hassan Khosravi,Ioannis N Daliakopoulos,Alexandre Marco Da Silva,Manuel Pulido Fernández,Enric Terol,Jesús Rodrigo-Comino,Gaspar Mora-Navarro

doi:10.3390/agriculture10070266

Abstract

Agricultural activities induce micro-topographical changes, soil compaction and structural changes due to soil cultivation, which directly affect ecosystem services. However, little is known about how these soil structural changes occur during and after the planting of orchards, and which key factors and processes play a major role in soil compaction due to cultivation works. This study evaluates the improved stock unearthing method (ISUM) as a low-cost and precise alternative to the tedious and costly traditional core sampling method, to characterize the changes in soil compaction in a representative persimmon orchard in Eastern Spain. To achieve this goal, firstly, in the field, undisturbed soil samples using metallic core rings (in January 2016 and 2019) were collected at different soil depths between 45 paired-trees, and topographic variations were determined following the protocol established by ISUM (January 2019). Our results show that soil bulk density (Bd) increases with depth and in the inter-row area, due to the effect of tractor passes and human trampling. The bulk density values of the top surface layers (0–12 cm) showed the lowest soil accumulation, but the highest temporal and spatial variability. Soil consolidation within three years after planting as calculated using the core samples was 12 mm, whereas when calculated with ISUM, it was 14 mm. The quality of the results with ISUM was better than with the traditional core method, due to the higher amount of sampling points. The ISUM is a promising method to measure soil compaction, but it is restricted to the land where soil erosion does not take place, or where soil erosion is measured to establish a balance of soil redistribution. Another positive contribution of ISUM is that it requires 24 h of technician work to acquire the data, whereas the core method requires 272 h. Our research is the first approach to use ISUM to quantify soil compaction and will contribute to applying innovative and low-cost monitoring methods to agricultural land and conserving ecosystem services.

Highlights

Soil degradation affects agricultural lands, which directly affects many ecosystems with clear benefits for human health such as agroecosystems
This study evaluated the improved stock unearthing method (ISUM) as a low-cost and precise alternative to the tedious and costly traditional core sampling method
ISUM samples were taken at 10 cm intervals from tree to tree, and our results demonstrate that soil compaction in persimmon orchards is due to soil compression because of tractor passes, which directly affect the soil topography

Summary

Introduction

Soil degradation affects agricultural lands, which directly affects many ecosystems with clear benefits for human health such as agroecosystems. Healthy soil ecosystems can give integral benefits to the productivity of food and sources, but non-sustainable land management is drastically defaulting this. This is because cultivation results in higher soil and water losses [1,2], soil organic matter depletion [3,4], nutrients delivery [5], reduction in soil fertility [6], and soil compaction enhancement [7]. Soil compaction is caused by the use of machinery, human trampling and the reduction of organic matter [8]. Mossadeghi-Björklund et al [12]

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Results

Discussion

Conclusion