ABSTRACT

Reliable data on the rate of cadmium (Cd) accumulation in soils that receive phosphorus (P) fertiliser is vital to help manage the impact of Cd in agricultural systems in New Zealand. Studies of the long-term P fertiliser trial at Winchmore, where soils have received 0, 17, or 34 kg P ha⁻¹ yr⁻¹ for > 60 years, have reported that soil Cd concentrations over the last 15 years have either plateaued or are still increasing. To address this discrepancy, new soil Cd analysis was conducted on a wider set of archived soil samples from the Winchmore trial, along with some re-analysis of soil samples for Cd. When soil Cd data from previous studies were combined with the more recent set of Cd data, regression analysis indicated soil Cd concentrations in the 17, or 34 kg P ha⁻¹ yr⁻¹ fertiliser treatments are still increasing linearly over time. It is recommended soil samples from the long-term Winchmore trial continue to be analysed for Cd to confirm long-term trends, avoiding short-term perturbations. Such long-term trials are invaluable for providing robust information that will help in the ongoing management of Cd in New Zealand.

摘要

获得磷 (P) 肥料的土壤中镉 (Cd) 积累率的可靠数据对于帮助管理 Cd 对新西兰农业系统的影响至关重要。在 Winchmore 进行的长期磷肥试验研究表明，土壤已接受 0、17 或 34 kg P ha ^-1 yr ^-1超过 60 年，据报告，过去 15 年土壤 Cd 浓度要么趋于稳定，要么仍在增加。为了解决这种差异，对来自 Winchmore 试验的一组更广泛的存档土壤样本进行了新的土壤 Cd 分析，同时对土壤样本的 Cd 进行了一些重新分析。当来自先前研究的土壤 Cd 数据与最近的一组 Cd 数据相结合时，回归分析表明土壤 Cd 浓度在 17 或 34 kg P ha ^-1yr ^-1施肥处理仍随时间线性增加。建议继续对 Winchmore 长期试验的土壤样本进行 Cd 分析，以确认长期趋势，避免短期扰动。此类长期试验对于提供有助于新西兰持续管理 Cd 的可靠信息非常宝贵。