Effects of Reducing Chemical Fertilisers Application on Tea Production and Soils Quality: An In Situ Field Experiment in Jiangsu, China

Abstract

In order to achieve sustainable development of the tea industry in China, it is necessary to reduce the use of chemical fertiliser rationally. With conventional fertilisation (CF) treatment as the control, five different chemical fertiliser-reduced regimes, including tea-specific formula fertiliser (T1), T1 + acidification amendment (T2), organic substitution based on T1 (T3), urea formaldehyde slow-release fertiliser (T4) and carbon-based organic fertiliser (T5), were conducted and evaluated on a green tea plantation from 2018 to 2021. The results showed that the spring tea yield of T1–T5 increased by 4.65–28.67%, while the free amino acids, tea polyphenols and sensory evaluation scores did not remarkably decrease. In addition, the T1–T5 treatments had a slight effect on soil acidification mitigation (except T2) and maintained the essential nutrients for tea production. Nutrient use efficiency improved, with agronomic efficiency (AE) increasing by 0.01–0.08 kg kg−1, shoot nutrient use efficiency (NUE) by 0.14–0.70% and partial factor productivity (PFP) by 0.05–0.18 kg kg−1. The net economic benefits also improved, with T1 showing a 135.28% increase, followed by T3 (67.53%), T2 (48.65%), T4 (38.07%) and T5 (33.35%). Overall, our results indicated that the T1 treatment could maintain the tea yield and quality while reducing the chemical fertiliser input and maximising the net economic benefit and AE.