Kibet P K, Mugwe J N, Korir N K, Mucheru-Muna M W, Ngetich F K, Mugendi D N
Department of Agricultural Science and Technology, Kenyatta University, P. O. Box 43844, 00100, Nairobi, Kenya.
Department of Environmental Sciences and Education, Kenyatta University, P. O. Box 43844, 00100, Nairobi, Kenya.
Heliyon. 2023 Jun 14;9(6):e17286. doi: 10.1016/j.heliyon.2023.e17286. eCollection 2023 Jun.
Acidic soils pose a major challenge for crop production in heavily weathered tropical soils, especially due to the high toxicity of aluminum (Al), low cation exchange capacity, and low availability of phosphorus (P) to plants. Lime application was recommended to alleviate soil acidity problems. Granular CaCO lime was introduced into the Kenyan market as an alternative to powdered CaCO and CaO-lime for small Kenyan farms, providing uniform distribution and efficient application. The aim of this study was therefore to investigate the effectiveness of different types of powdered and granular lime individually and in combination with mineral fertilizers in improving soil properties and maize yield. The study was conducted at two sites, Kirege (extremely acidic) and Kangutu (moderately acidic). Experiments were conducted in a randomized complete block design repeated four times in two consecutive seasons: long rain (LR) in 2016 and short rain (SR) in 2016. Three types of lime were applied before planting. Selected chemical properties of the soil were analyzed before and after the experiment. Maize and stover yield data were collected and analyzed. Results showed that lime application significantly increased soil pH and decreased exchangeable acidity. Powdered calcium carbonate (CaCO) showed the highest pH increase in both extreme (+19%) and moderate (+14%) acid sites. All types of lime and fertilizer applications alone significantly increased the available soil P at both the seasonal and site levels. However, maize grain yield was lower with fertilizer alone or lime alone than with lime and fertilizer combination. Powdered CaCO+ fertilizer was found to give the highest grain yields on both very acidic (5.34 t ha) and moderately (3.71 t ha) acid sites. In the study, combining powdered CaCO lime with fertilizers was most effective in improving acidic soils by decreasing soil acidity and increasing available phosphorus, which ultimately increased grain yield. The results of this study recommend the use of powdered CaCO as an effective and practical solution for farmers facing soil acidification problems.
酸性土壤对热带地区严重风化土壤上的作物生产构成重大挑战，特别是因为铝（Al）的高毒性、低阳离子交换量以及植物对磷（P）的低有效性。建议施用石灰来缓解土壤酸度问题。粒状碳酸钙石灰作为肯尼亚小农场粉状碳酸钙和氧化钙石灰的替代品被引入肯尼亚市场，具有分布均匀和施用高效的特点。因此，本研究的目的是调查不同类型的粉状和粒状石灰单独使用以及与矿物肥料混合使用对改善土壤性质和玉米产量的效果。该研究在两个地点进行，基雷格（极酸性）和坎古图（中度酸性）。试验采用随机完全区组设计，在2016年的两个连续季节重复进行四次：2016年长雨季（LR）和短雨季（SR）。在种植前施用了三种类型的石灰。在试验前后分析了土壤的选定化学性质。收集并分析了玉米和秸秆产量数据。结果表明，施用石灰显著提高了土壤pH值并降低了交换性酸度。粉状碳酸钙（CaCO）在极酸性（提高19%）和中度酸性（提高14%）位点均表现出最高的pH值升高。所有类型的石灰和肥料单独施用在季节和位点水平上均显著提高了土壤有效磷含量。然而，单独施用肥料或石灰时的玉米籽粒产量低于石灰与肥料混合施用时的产量。发现在极酸性（5.34吨/公顷）和中度酸性（3.71吨/公顷）位点，粉状CaCO+肥料的籽粒产量最高。在本研究中，将粉状CaCO石灰与肥料混合使用在改善酸性土壤方面最有效，通过降低土壤酸度和增加有效磷，最终提高了籽粒产量。本研究结果建议将粉状CaCO作为面临土壤酸化问题的农民的一种有效且实用的解决方案。
