Crop and soil nitrogen responses to phosphorus and potassium fertilization and drip irrigation under processing tomato

• Published in: Nutrient cycling in agroecosystems Vol. 93; no. 2; pp. 151 - 162
• Main Authors: Liu, K., Zhang, T. Q., Tan, C. S., Astatkie, T., Price, G. W.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2012; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Drip irrigation; Environmental impact; Fertilization; Fertilizers; Fruits; Growing season; Harvesting; Irrigation; Life Sciences; Nitrogen; Original Article; Phosphorus; Potassium; Residual soils; Spatial distribution; Tomatoes; Water depth; Water management; Water shortages; Nitrogen uptake; Nitrogen balance; Soil profile nitrogen; Drip irrigation; Nitrogen harvest index
• ISSN: 1385-1314; 1573-0867
• DOI: 10.1007/s10705-012-9506-0

Shortage of water or nutrient supplies can restrict the high nitrogen (N) demand of processing tomato, leaving high residual soil N resulting in negative environmental impacts. A 4-year field experiment, 2006–2009, was conducted to study the effects of water management consisting of drip irrigation (DI) and non-irrigation (NI), fertilizer phosphorus (P) rates (0, 30, 60, and 90 kg P ha −1 ), and fertilizer potassium (K) rates (0, 200, 400, and 600 kg K ha −1 ) on soil and plant N when a recommended N rate of 270 kg N ha −1 was applied. Compared with the NI treatment, DI increased fruit N removal by 101 %, plant total N uptake by 26 %, and N harvest index by 55 %. Consequently, DI decreased apparent field N balance (fertiliser N input minus plant total N uptake) by 28 % and cumulative post-harvest soil N in the 0–100 cm depth by 33 %. Post-harvest soil N concentration was not affected by water management in the 0–20 cm depth, but was significantly higher in the NI treatment in the 20–100 cm depth. Fertilizer P input had no effects on all variables except for decreasing N concentration in the stems and leaves. Fertilizer K rates significantly affected plant N utilization, with highest fruit N removal and plant total N uptake at the 200 kg K ha −1 treatment; therefore, supplementing K had the potential to decrease gross N losses during tomato growing seasons. Based on the measured apparent field N balance and spatial distribution of soil N, gross N losses during the growing season were more severe than expected in a region that is highly susceptible to post-harvest soil N losses.