Combined application of soluble organic and chemical fertilizers in drip fertigation improves nitrogen use efficiency and enhances tomato yield and quality.

Background: Sustainable greenhouse tomato production requires optimal fertilizer management to achieve the double-win strategy of producing high yields and maximizing profits with less environmental pollution. The objective of this study was to seek an optimal fertilization strategy maintaining high productivity of greenhouse tomato, improving nitrogen use efficiency and reducing nitrate leaching risk.
Results: The combined application of soluble organic and chemical fertilizers for topdressing (SOSC) not only produced more fruit yield (75.18 Mg ha ^-1 ) and plant dry matter (10 449.12 kg ha ^-1 ), but also enhanced plant nutrients uptake, nitrogen recovery efficiency (39.22%), nitrogen agronomic efficiency (176.78 kg kg ^-1 ), soluble solids, vitamin C and lycopene content in tomato fruits compared with the other treatments, that is chicken manures for basal application and chemical fertilizer for topdressing (CC), soluble organic fertilizer for topdressing (SO) and soluble chemical fertilizer for topdressing (SC). In terms of soil nutrients residue, SOSC had no obvious NO ₃ ^- -N accumulation area in the 0-60 cm soil layer, unlike large accumulation in the soil layer below 30 cm in SO and SC.
Conclusion: The combined application of soluble organic and chemical fertilizers is highly recommended to sustain fruit yield, improve nitrogen use efficiency and reduce soil degradation risks in commercial greenhouse tomato production.
(© 2020 Society of Chemical Industry.)