Enesi Rebecca Oiza, Dyck Miles F, Thilakarathna Malinda S, Strelkov Stephen E, Gorim Linda Yuya
Department of Agriculture, Food & Science, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada.
Department of Renewable Resource, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada.
Heliyon. 2024 Aug 28;10(17):e37106. doi: 10.1016/j.heliyon.2024.e37106. eCollection 2024 Sep 15.
Spatial variability in soil pH is a major contributor to within-field variations in soil fertility and crop productivity. An improved understanding of the spatial variability of soil pH within agricultural fields is required to determine liming requirements for precision farming. This study with the use of proximal sensors, firstly assessed the spatial pattern of soil pH and how it can be used to determine site-specific, spatially variable lime requirements. Secondly, the effects of soil pH on soil concentrations of nitrate nitrogen (N0-N), phosphorus (P), potassium (K), sulfur (SO-S), calcium (Ca), magnesium (Mg), soil organic matter (SOM), aluminum (Al), and manganese (Mn) were assessed in three study fields in central Alberta, Canada. Soil pH varied between 4.5 and 7.5 across all field sites. The field-scale coefficient of variation (CV %) for soil pH, Al and Mn ranged between 4.39 and 7.50 %, 7.33-13.72 %, and 7.33-13.72 % across the three sites. The other soil properties showed low, moderate, and high variability, with field-scale CVs ranging between 6.39 and 17.70 % for SOM and 24.33-91.39 % for SO-S. Soil pH exhibited positive correlations with both Ca and Mg, across all fields. Negative correlations were observed between soil pH and Al across all fields. A principal component analysis (PCA) was performed for all soil parameters and two principal components accounted for 50 %, 54.9 %, and 76.8 % of the total variance in field 1, field 2, and field 3, respectively. Geostatistical semivariance indicated a strong spatial dependence of all chemical parameters across fields. Large regions within a field were strongly acidic (pH < 5.5) and required lime applications ranging from 0 to 6 t ha. We conclude that proximal soil sensors can be calibrated to soil properties, enabling variable rate lime recommendations on spatially variable fields for the management of soil acidity.
土壤pH值的空间变异性是造成田间土壤肥力和作物生产力差异的主要因素。为了确定精准农业的石灰需求量，需要更好地了解农田土壤pH值的空间变异性。本研究使用近距离传感器，首先评估了土壤pH值的空间格局以及如何利用它来确定特定地点、空间变异的石灰需求量。其次，在加拿大艾伯塔省中部的三个研究田块中，评估了土壤pH值对土壤中硝态氮（N0-N）、磷（P）、钾（K）、硫（SO-S）、钙（Ca）、镁（Mg）、土壤有机质（SOM）、铝（Al）和锰（Mn）浓度的影响。所有田块的土壤pH值在4.5至7.5之间变化。三个田块土壤pH值、Al和Mn的田间尺度变异系数（CV%）在4.39%至7.50%、7.33%至13.72%和7.33%至13.72%之间。其他土壤性质表现出低、中、高变异性，SOM的田间尺度CV在6.39%至17.70%之间，SO-S的田间尺度CV在24.33%至91.39%之间。在所有田块中，土壤pH值与Ca和Mg均呈正相关。在所有田块中，土壤pH值与Al之间均呈负相关。对所有土壤参数进行了主成分分析（PCA），第一主成分和第二主成分分别解释了第1块田、第2块田和第3块田总方差的50%、54.9%和76.8%。地统计半方差表明，所有化学参数在田间具有很强的空间依赖性。田间大片区域呈强酸性（pH < 5.5），需要施用0至6 t/ha的石灰。我们得出结论，近距离土壤传感器可以根据土壤性质进行校准，从而在空间变异的田块上实现可变施用量的石灰推荐，以管理土壤酸度。
