Organic soil amendments can improve soil health but their role in improving N management has not been well quantified. The objectives of this research were to evaluate the influence of biochar and manure compost application on crop yield, N uptake, changes in soil and environmental losses and to use the information to assess the N requirement and project fertilization needs. A field experiment was conducted in California, USA, with processing tomato (Lycopersicon esculentum Mill.) grown first, followed by garlic (Allium sativum). The soil was a sandy loam with a pH of 7.2 and CEC of 9.1 cmol(+) kg⁻¹. Treatments included two biochar products, derived from almond shell or softwood feedstocks, applied at 20 or 40 tonnes (t) ha⁻¹, dairy manure compost at 20 t ha⁻¹, combinations of the manure and the biochar (each at 20 t ha⁻¹), and a control. Although biochar and manure applications improved the surface soil organic C and total N content, no significant effects on crop yield, biomass and N uptake, as well as ammonia volatilization and leaching loss, were observed. The amount of N sequestered by plants ranged from 3.2 to 3.8 and 9.9 to 10.0 kg N Mg⁻¹ to produce fresh tomato fruits and garlic bulbs, respectively. However, about half of the N for tomato and 93% for garlic plants were removed from soil by harvesting. The N sequestered per unit biomass (or yield) production appears a stable parameter, which can be used to reliably project fertilization needs that target high NUE and minimal loss to the environment.

中文翻译：

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生物炭和粪肥施用对番茄和大蒜作物的氮命运和固存没有显着影响：美国加利福尼亚州的田间试验

有机土壤改良剂可以改善土壤健康，但它们在改善氮管理方面的作用尚未得到很好的量化。本研究的目的是评估生物炭和粪肥堆肥应用对作物产量、氮吸收、土壤变化和环境损失的影响，并利用这些信息评估氮需求和项目施肥需求。在美国加利福尼亚州进行了一项田间试验，首先种植加工番茄（Lycopersicon esculentum Mill.），然后种植大蒜（Allium sativum）。土壤是沙质壤土，pH 值为 7.2，CEC 为 9.1 cmol(+) kg ^-1。处理包括两种来自杏仁壳或软木原料的生物炭产品，施用量为 20 或 40 吨 (t) ha ^{-1、20 t ha -1}的奶牛粪堆肥、粪肥和生物炭的组合（各 20 t ha ^-1）和对照。虽然生物炭和粪肥的应用提高了表层土壤有机碳和总氮含量，但对作物产量、生物量和氮吸收以及氨挥发和淋失损失没有显着影响。植物吸收的 N 量范围为 3.2 至 3.8 和 9.9 至 10.0 kg N Mg ^-1分别生产新鲜的番茄果实和大蒜鳞茎。然而，通过收获从土壤中去除了大约一半的番茄氮和 93% 的大蒜植物。每单位生物量（或产量）产生的氮封存似乎是一个稳定的参数，可用于可靠地预测以高 NUE 和对环境的损失最小为目标的施肥需求。