Efficacy of a Phosphate-Charged Soil Material in Supplying Phosphate for Plant Growth in Soilless Root Media

Table 2

Phosphorus concentration in bulk solutions of root media amended with no soil material (control) and six soil material treatment combinations containing 5 or 10% soil material (v : v) charged with 0, 2.2, or 6.5 mg·g⁻¹ phosphate-P during three successive tomato seedling crops.

Trt	Crop 1 (DAT)						Crop 2 (DAT)					Crop 3 (DAT)
	4	11	16	21	24	37	0	11	16	25	27	0	15	21	27	36
	Bulk solution P (mg·dm^−3)
Control	8.85	6.19	13.72	4.39	5.87	18.66	16.79	13.53	13.39	8.83	17.48	15.97	22.05	21.85	29.71	33.42
0 P-5%	0.39	0.57	0.46	0.34	0.21	0.53	1.18	2.25	3.29	1.43	1.86	2.71	4.36	5.48	7.68	17.34
0 P-10%	0.33	0.34	0.33	0.30	0.25	0.18	0.14	0.47	0.41	0.49	0.57	0.67	1.01	1.19	2.28	7.58
2.2 P-5%	2.40	1.90	0.97	0.51	0.33	0.20	0.23	0.34	0.23	0.27	0.19	0.30	0.16	0.15	0.16	0.13
2.2 P-10%	2.29	1.77	1.28	0.75	0.51	0.28	0.38	0.49	0.32	0.32	0.23	0.37	0.19	0.18	0.20	0.21
6.5 P-5%	43.30	29.18	20.06	5.98	4.08	0.78	1.02	2.26	1.34	0.46	0.35	0.69	0.43	0.21	0.17	0.23
6.5 P-10%	58.00	41.24	30.65	15.69	10.47	2.89	5.02	8.73	4.81	1.66	1.08	3.64	1.43	0.81	0.54	0.45
	1.27						1.32					1.15

Bold italic values within treatments were associated with symptoms of P deficiency when the sample was collected.
Days after transplanting of 20-day-old tomato seedlings.
values are for comparing soil material treatments within a given crop or crops within a given soil material treatment.