Agbede Taiwo Michael
Department of Agronomy, Adekunle Ajasin University, P.M.B. 001, Akungba-Akoko, Ondo State, Nigeria.
Heliyon. 2021 Jun 24;7(6):e07391. doi: 10.1016/j.heliyon.2021.e07391. eCollection 2021 Jun.
Tillage, biochar, poultry manure, NPK fertilizer and their combined application could improve soil quality, sustainability and carrot productivity. The effects of two tillage treatments: conventional tillage (CT) and reduced tillage (RT) each combined with 30 Mg ha biochar (B), 10 Mg ha poultry manure (PM), 300 kg ha NPK 15-15-15 fertilizer, 150 kg ha NPK 15-15-15 fertilizer +15 Mg ha biochar +5 Mg ha poultry manure and a control (no biochar/poultry manure/NPK fertilizer) on soil properties, growth and carrot yield were investigated. The research was carried out for two consecutive growing seasons (2018 and 2019) at Owo in the forest-savanna transition zone of Nigeria on a sandy loam. The experiment was laid out in a randomized complete block design in a factorial combination of ten treatments and replicated three times. Reduced tillage had relatively lower soil bulk density, penetration resistance, dispersion ratio and temperature, and had significantly higher (p = 0.05) soil aggregate stability, mean weight diameter, porosity and water content than conventional tillage and these resulted in higher soil pH, organic C, N, P, K, Ca and Mg, growth and fresh root yield of carrot compared with conventional tillage. Reduced tillage increased fresh carrot root yield by 2.3 Mg ha and 2.6 Mg ha for the first and second growing seasons, respectively, compared with conventional tillage, which corresponded to a 11.1% increment for both years. Application of biochar alone, poultry manure alone and complementary application of NPK fertilizer, biochar and poultry manure decreased soil bulk density, penetration resistance, dispersion ratio and temperature and increased soil water content, porosity, aggregate stability and mean weight diameter whereas NPK fertilizer did not improve these soil physical properties. Biochar alone, poultry manure alone, NPK fertilizer alone and combined application of NPK fertilizer, biochar and poultry manure increased soil total N, available P, and exchangeable K, Ca and Mg concentrations compared with the control. Application of biochar alone improved soil pH, OC, K, Ca and Mg better than the NPK fertilizer. Poultry manure improved soil pH, OC, N, K, Ca and Mg better than the NPK fertilizer. Combined application of NPK fertilizer, biochar and poultry manure at sub-optimal rates gave higher soil N, P, K, Ca and Mg concentrations, higher plant, number of leaves, root length, root diameter and fresh carrot root yield compared with NPK fertilizer or biochar or poultry manure alone. Compared with control, NPK fertilizer alone, biochar alone, poultry manure alone and mixture of NPK fertilizer, biochar and poultry manure increased fresh carrot root yield by 43, 24, 46 and 76%, respectively. Reduced tillage in combination with NPK fertilizer, biochar and poultry manure gave the highest fresh carrot root yield. The results indicated that reduced tillage in combination with NPK fertilizer, biochar and poultry manure prove to be an effective and sustainable management strategy for improving soil quality and carrot yield than conventional tillage in combination with NPK fertilizer, biochar and poultry manure.
耕作、生物炭、家禽粪便、氮磷钾肥料及其组合施用可改善土壤质量、可持续性和胡萝卜产量。研究了两种耕作处理方式：传统耕作（CT）和少耕（RT），每种方式分别与30 Mg/ha生物炭（B）、10 Mg/ha家禽粪便（PM）、300 kg/ha氮磷钾15 - 15 - 15肥料、150 kg/ha氮磷钾15 - 15 - 15肥料 + 15 Mg/ha生物炭 + 5 Mg/ha家禽粪便以及对照（不施生物炭/家禽粪便/氮磷钾肥料）对土壤性质、胡萝卜生长和产量的影响。该研究于2018年和2019年在尼日利亚森林 - 稀树草原过渡带的奥沃连续两个生长季进行，土壤为砂壤土。试验采用随机完全区组设计，有十种处理方式的析因组合，重复三次。与传统耕作相比，少耕的土壤容重、穿透阻力、分散率和温度相对较低，土壤团聚体稳定性、平均重量直径、孔隙度和含水量显著更高（p = 0.05），这使得与传统耕作相比，少耕的土壤pH值、有机碳、氮、磷、钾、钙和镁含量更高，胡萝卜的生长和鲜根产量也更高。与传统耕作相比，少耕在第一个和第二个生长季的胡萝卜鲜根产量分别增加了2.3 Mg/ha和2.6 Mg/ha，两年的增幅均为11.1%。单独施用生物炭、单独施用家禽粪便以及氮磷钾肥料、生物炭和家禽粪便的互补施用降低了土壤容重、穿透阻力、分散率和温度，增加了土壤含水量、孔隙度、团聚体稳定性和平均重量直径，而氮磷钾肥料并未改善这些土壤物理性质。与对照相比，单独施用生物炭、单独施用家禽粪便、单独施用氮磷钾肥料以及氮磷钾肥料、生物炭和家禽粪便的组合施用提高了土壤总氮、有效磷以及交换性钾、钙和镁的浓度。单独施用生物炭比氮磷钾肥料能更好地改善土壤pH值、有机碳、钾、钙和镁含量。家禽粪便比氮磷钾肥料能更好地改善土壤pH值、有机碳、氮、钾、钙和镁含量。与单独施用氮磷钾肥料、生物炭或家禽粪便相比，以次优比例组合施用氮磷钾肥料、生物炭和家禽粪便能使土壤中氮、磷、钾、钙和镁的浓度更高，植株更高，叶片数更多，根长更长，根直径更大，胡萝卜鲜根产量更高。与对照相比，单独施用氮磷钾肥料、单独施用生物炭、单独施用家禽粪便以及氮磷钾肥料、生物炭和家禽粪便的混合物使胡萝卜鲜根产量分别提高了43%、24%、46%和76%。少耕与氮磷钾肥料、生物炭和家禽粪便相结合时胡萝卜鲜根产量最高。结果表明，与传统耕作结合氮磷钾肥料、生物炭和家禽粪便相比，少耕结合氮磷钾肥料、生物炭和家禽粪便是一种提高土壤质量和胡萝卜产量的有效且可持续的管理策略。
