Habteweld A, Brainard D, Kravchencko A, Grewal P S, Melakeberhan H
Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32611-0620.
Department of Horticulture, Michigan State University, East Lansing, MI, 48824.
J Nematol. 2020 Oct 21;52. doi: 10.21307/jofnem-2020-111. eCollection 2020.
Soil nutrient management system characterized by reduced input of inorganic fertilizers integrated with organic amendments is one of the alternatives for reducing deleterious environmental impact of synthetic fertilizers, suppressing soil-borne pests and diseases, and improving soil health and crop yield. A hypothesis of the present study was that lower rates of urea mixed with higher rates of plant compost (PC) would improve nematode community structure, soil food web condition, soil biological, and physiochemical properties, and yield and quality of a processing carrot () cultivar. Urea and PC were each applied at 135 kg nitrogen (N)/ha alone or at 3:1, 1:1, and 1:3 ratios annually during the 2012 to 2014 growing seasons. A non-amended check served as a control. Nematode community was analyzed from soil samples collected approximately 4-week intervals from planting to 133 days after planting each year. Soil respiration, as a measure of soil biological activity, and soil physiochemical properties were determined from soils collected at planting and at harvest in 2012 and 2013. Results showed that PC alone, and U1:PC1 resulted in soil food web structure significantly above 50 at harvest in 2014. Urea significantly decreased end-of-season soil pH, but increased NO-N compared with the other treatments. While the herbivore population density was low, abundances of and were negatively correlated with carrot fresh weight of marketable carrot. Overall, results suggest that integrating lower rates of urea and higher rates of PC are likely to increase soil biological activity, soil pH, and phosphorus content.
以减少无机肥料投入并结合有机改良剂为特征的土壤养分管理系统，是减少合成肥料对环境的有害影响、抑制土传病虫害以及改善土壤健康和作物产量的替代方案之一。本研究的一个假设是，较低比例的尿素与较高比例的植物堆肥（PC）混合，将改善线虫群落结构、土壤食物网状况、土壤生物学和理化性质，以及加工胡萝卜（）品种的产量和品质。在2012年至2014年生长季节，每年分别以135千克氮（N）/公顷的用量单独施用尿素和PC，或以3:1、1:1和1:3的比例施用。不进行改良的对照作为控制组。每年从种植到种植后133天，每隔约4周采集土壤样本分析线虫群落。土壤呼吸作为土壤生物活性的指标，以及土壤理化性质，是根据2012年和2013年种植时和收获时采集的土壤测定的。结果表明，单独施用PC以及尿素与PC以1:1比例混合（U1:PC1），在2014年收获时土壤食物网结构显著高于50。与其他处理相比，尿素显著降低了季末土壤pH值，但增加了硝态氮含量。虽然食草动物种群密度较低，但 和 的丰度与可上市胡萝卜的鲜重呈负相关。总体而言，结果表明，较低比例的尿素与较高比例的PC混合，可能会提高土壤生物活性、土壤pH值和磷含量。
