Table 7. Effect of P rates and K rates on corn and soybean grain yields under two tillage systems for two locations in southern Illinois, 2001-04.

Illinois Fertilizer Conference Proceedings
January 26-28, 2006

Variable	Dixon Springs						Belleville						Over– all Ave.
Variable	01	02	03	04	05	Ave	01	02	03	04	05	Ave	Over– all Ave.
	----------bu⁄acre Grain Yield-------
Chisel Till. Soybean
AP & AK	41	38	40	47	45	42	58	75	57	61	66	63	53
BP & BK (corn)	42	34	48	46	46	43	58	74	58	61	67	64	53
BP & BK (soy)	42	35	40	42	51	42	57	73	56	61	65	62	52
BP(corn) & BK(soy)	46	38	38	44	44	42	58	74	53	61	67	62	52
BP(soy) & BK(corn)	44	30	40	48	46	42	58	74	57	61	68	64	53
LSD	7.7	5.3	5.1	5.5	NS		NS	NS	NS	NS	NS
No–Till Soybean
AP & AK	49	41	39	62	57	50	54	70	55	76	74	66	58
BP & BK (corn)	48	44	41	58	58	50	54	70	59	74	68	65	57
BP & BK (soy)	45	43	39	62	65	51	55	70	52	78	74	66	58
BP(corn) & BK(soy)	42	41	39	59	54	47	54	70	52	74	71	64	56
BP(soy) & BK(corn)	49	44	37	63	59	50	55	69	53	77	76	66	58
LSD	NS	NS	NS	4.1	6.8		NS	NS	5.6	NS	4.8

† Rates for Dixon Springs CT were 1.5× P rates and 2× K rates at other locations. In 2004, rates for NT at DS increased to 1.5× P and 2× K rates.

‡ Means for P rates averaged across K rates and means for K rates averaged across P rates.