Response of Sugarcane in a Red Ultisol to Phosphorus Rates, Phosphorus Sources, and Filter Cake

Table 2

Stalk phosphorus accumulation (P-stalk) in leaves and apical meristem (P-straw), total (P-total), length (SL), diameter (SD), stalk number (SN), and the productivity of straw and stalks of sugarcane grown in Eutrophic Red Ultisol, as a function of phosphate fertilizer with different P sources, P application rates, and filter cake.

	P-stalks	P-straw	P-total	SL	SD	SN	Straw	Stalks
	kg ha^−1 of P			m	mm		t ha^−1
P sources
Araxa	24.8	13.1	37.9	3.4	28.5	15	21.2	217.4
Bayovar	23.5	12.8	36.3	3.4	28.7	15	21.3	209.7
Triple superphosphate	25.4	15.3	40.7	3.4	28.6	16	22.0	221.0
P2O5 rates
0	20.8	9.9	30.7	3.4	28.4	13	18.7	182.0
90	25.2	13.7	38.9	3.4	28.6	17	22.3	221.0
180	25.9	16.9	42.8	3.5	28.5	16	24.2	232.0
360	26.3	14.4	40.7	3.3	28.8	16	20.8	229.1
Filter cake
Presence	28.9	15.0	43.9	3.4	28.6	16	22.3	222.5
Absence	20.3	12.5	32.8	3.4	28.6	15	20.7	209.6
	test
Source	1.3^ns	2.6^ns	2.9^ns	0.5^ns	0.1^ns	0.4^ns	0.2^ns	1.3^ns
Rate	6.4	8.6	12.4	1.8^ns	0.5^ns	5.9	3.5	16.0
Filter cake	73.0	6.6	54.7	1.1^ns	0.1^ns	0.0^ns	1.7^ns	5.0
Source × rate	0.5^ns	0.6^ns	0.5^ns	0.2^ns	0.3^ns	1.1^ns	0.7^ns	1.0^ns
Source × cake	0.5^ns	0.6^ns	1.0^ns	1.0^ns	0.8^ns	0.2^ns	0.6^ns	0.1^ns
Rate × cake	1.6^ns	0.3^ns	1.4^ns	0.7^ns	1.3^ns	2.2^ns	0.4^ns	1.4^ns
Source × rate × cake	0.7^ns	0.6^ns	0.7^ns	1.1^ns	0.3^ns	0.5^ns	0.4^ns	0.1^ns
CV, %	17.4	29.3	16.7	5.3	3.5	14.9	24.1	11.4

, and ns: significant (, ) and insignificant, respectively ( test).