CHAPTER 4. FERTILIZER CONSUMPTION BY CROP

Statistical data concerning the consumption of fertilizers by crops are unavailable and for the sake of this report an indirect approach had to be used. This approach is based on so-called 'coefficients of preference'. This coefficient represents the ratio of the actual fertilizer rate for a given crop to the average rate applied to one ha of agricultural land. Coefficients of preference were calculated from the survey conducted during the past five years on the representative set of farms in Poland.

Unfortunately the coefficients of preference concern the total amount of NPK and do not separate out the individual nutrients. Consequently some crops seem to be under-estimated and others over-estimated with respect to calculated rates of nitrogen, phosphorus and/or potassium fertilizers. The previous method under-estimated the rates on potatoes, rapeseed and vegetables, and over-estimated those on maize, grassland and perennial fodder crops. The main drawback of both methods is the assumption that the whole area of a given crop is fertilized, while some farmers do not apply fertilizers at all or use fertilizers only on a few, high profitable crops.

Nitrogen

The actual (or most probable) rates of nitrogen for crops grown in regions of Poland are presented in Table 14. The rates of nitrogen are the highest for sugar and fodder beets (in spite of manure application), maize, rapeseed and wheat. High rates of nitrogen are also applied on vegetables and triticale. The lowest rates are applied on rye, oats, pulses and fodder crops. The low rate for grassland is to a certain extent misleading because there are no separate coefficients of preference for meadows and pastures. Part of the area of pastures is, moreover, not fertilized. However, due to the alternative utilization of most grassland in Poland (for both hay and grazing) it seems practical to calculate the average rate of nitrogen for the total grassland area.

Table 14. Actual rates of nitrogen applied to crops in the regions of Poland (averages 1999-2001, kg N/ha)

Region or province	Grassland	Wheat	Grain maize	Potatoes	Sugar beet
Dls	29	49	62	36	91
Kuj	59	98	124	75	182
Lub	34	56	71	41	105
Lus	53	88	112	65	164
Lod	46	77	98	57	145
Mal	30	51	64	37	95
Maz	35	58	74	43	108
Opl	46	77	97	56	143
Pdk	18	31	39	22	57
Pod	39	66	83	48	123
Pom	50	83	105	61	155
Sls	32	53	68	39	100
Swi	28	46	59	34	87
Wrm	43	71	90	52	133
Wlp	56	93	118	68	173
Zpm	54	89	113	66	167
Poland	39	65	82	47	121

Phosphorus

Present phosphorus rates are presented in Table 15. These rates are the highest for sugar and fodder beet, maize and rapeseed. Rates of phosphorus per hectare of agricultural land are higher in Opl and Pom regions than the average for Poland, however in Pom region the share of set-aside (unfertilized) land is three times higher in comparison to Opl region. Therefore the rates of phosphorus for the individual crops in Pom region far exceed those in Opl region.

Table 15. Actual rates of phosphorus applied to crops in the regions of Poland
(averages 1999-2001, kg P₂O₅/ha)

Region or province	Rapeseed	Wheat	Grain maize	Potatoes	Sugar beet
Dls	32	22	28	16	41
Kuj	31	21	27	16	40
Lub	37	25	32	18	47
Lus	42	28	36	21	53
Lod	26	18	223	13	34
Mal	41	28	35	20	52
Maz	43	29	37	21	55
Opl	37	25	32	19	47
Pdk	24	16	21	12	31
Pod	38	26	33	19	49
Pom	61	41	52	30	77
Sls	24	16	21	12	31
Swi	28	19	24	14	36
Wrm	29	20	25	14	37
Wlp	35	24	30	18	45
Zpm	33	23	29	17	43
Poland	33	23	29	17	43

Potassium

The rates of potassium application are presented in Table 16. They are highest for sugar beet, maize and rapeseed and lowest for rye, pulses and fodder crops. Care is taken with potassium fertilization in western and northern Poland but it is neglected in the middle and eastern parts of the country.

Table 16. Present rates of potash applied to crops in the regions of Poland
(averages 1999-2000, kg K₂O/ha)

Region or province	Rapeseed	Wheat	Grain maize	Potatoes	Sugar beet
Dls	38	26	33	19	49
Kuj	42	29	36	21	53
Lub	43	29	37	21	55
Lus	45	31	39	22	57
Lod	31	21	26	15	39
Mal	43	29	37	222	55
Maz	52	36	45	26	66
Opl	60	41	52	30	77
Pdk	26	18	23	13	33
Pod	41	28	35	20	52
Pom	78	53	67	39	99
Sls	35	24	30	17	44
Swi	25	17	22	13	32
Wrm	38	26	33	19	49
Wlp	48	33	42	24	62
Zpm	55	38	48	28	71
Poland	42	29	36	21	53