Improving fertilizer-depot exploitation and maize growth by inoculation with plant growth-promoting bacteria: from lab to field

Chemical and Biological Technologies in Agriculture

Table 1 Treatments (field experiments 2014 and 2015)

		Starter N and P	Additional P	Additional N	BE
Treatments 2014
1	Zero	–	–	–	–
2	+P	MAP	TSP	NH4-Broad	–
3	NH4-Broad	MAP	–	NH4-Broad	–
4	NH4-Broad*BE1	MAP	–	NH4-Broad	BE1
5	NH4-Broad*BE2	MAP	–	NH4-Broad	BE2
6	NH4-Depot	MAP	–	NH4-Depot	–
7	NH4-Depot*BE1	MAP	–	NH4-Depot	BE1
8	NH4-Depot*BE2	MAP	–	NH4-Depot	BE2
Treatments 2015
1	Zero	–	–	–	–
2	+P	DAP	TSP	NH4-Broad	–
3	NH4-Broad	DAP	–	NH4-Broad	–
4	NH4-Broad*BE1	DAP	–	NH4-Broad	BE1
5	NH4-Broad*BE2	DAP	–	NH4-Broad	BE2
6	NH4-Depot	DAP	–	NH4-Depot	–
7	NH4-Depot*BE1	DAP	–	NH4-Depot	BE1
8	NH4-Depot*BE2	DAP	–	NH4-Depot	BE2

Starter (starter fertilizers placed 5 × 5 cm to seeds) MAP mono-ammonium phosphate, 17 kg N and 35 kg P ha⁻¹, DAP di-ammonium phosphate, 28.8 kg N and 32 kg P ha⁻¹, TSP triple superphosphate broadcasted and incorporated at 10 cm depth before sowing, 2014, 133 kg P; 2015, 130 kg P ha⁻¹, NH4-Broad stabilized (NH₄)₂SO₄ broadcasted over the crop canopy 2014, 135 kg N; broadcasted and incorporated before sowing 2015, 100 kg N ha⁻¹, NH4-Depot stabilized concentrated (NH₄)₂SO₄ solution in water placed as a depot at 10 cm soil depth, 2014, 135 kg N; 2015, 100 kg N ha⁻¹, BE1 Pseudomonas sp. DSMZ 13134, BE2 Bacillus amyloliquefaciens FZB42; BE application: 2014, broadcast/incorporation 1 × 10⁶ CFU g⁻¹ soil DM; 2015, placement of a band of BE-treated pumice stones in the sowing row; 0.13 × 10⁶ CFU g⁻¹ soil DM