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Fine-tuning a nitrogen budget system for sugarbeets produced under sprinkler and flood irrigation

J. Eckhoff¹, J. Bergman¹, C. Flynn¹, and K. Rasmussen²

Previous crops were malt barley in 2004, sugarbeets in 2003, and malt barley in 2002. Residual soil N to 4 feet was 73 lb/ac and residual soil P to 6 inches was 18 ppm. Five rates of liquid 28-0-0 were applied April 26, 2005. A check treatment with no applied N was included.

Plots were planted to stand with the variety AC927 on April 26 with a commercial six-row planter. Ro-Neet 6E (3.5 lb AI/ac) and Counter (1 lb AI/ac) were applied in 7” bands at planting. Severe winds damaged plots in mid May, and plots were replanted on May 24. Betamix was applied on June 3 (1.5 pt/ac) and on June 14 (2.0 pt/ac). Plots were hand-weeded on July 7 and August 5. Headline (9.0 oz/ac) was applied by ground rig on August 11.

Sprinkler plots were irrigated May 5, Jul 8, Jul 14, Jul 20, Aug 1, Aug 15, Aug 23, and Sep 6. Flood irrigated plots were irrigated on Jun 9, Jul 21, Aug 2, Aug 24, and Sep 8. Precipitation for April 1 – September 30 in 2005 was 10.16 inches. Average precipitation for April - September period (57-year average) is 10.71 inches. Plots were harvested on September 27.

Stand, yield, and quality of sugarbeets grown under flood and sprinkler irrigation with six rates of available N, 2005.

available N to 4 ft, lb/ac	Irrigation	Harvest Stand, plnts/ac	Percent sucrose	Root Yield T/acre	Sucrose Yield, Lb/acre	Na ppm	K ppm	Amino-N ppm	sucrose loss to molasses	Extract- able Sucrose lb/acre
73	flood	39,450	19.45	23.9	9290	242	1722	145	0.98	8821
100	flood	38,480	19.30	23.4	9026	272	1653	154	0.98	8567
125	flood	40,660	19.27	25.3	9758	265	1592	157	0.96	9272
150	flood	38,840	19.09	26.0	9935	312	1763	163	1.06	9383
175	flood	34,490	18.91	25.6	9692	291	1670	172	1.02	9168
200	flood	36,910	18.61	25.4	9467	353	1680	173	1.06	8927
LSD 5%		NS	0.35	1.3	532	NS	73	26	0.06	518
73	sprinkler	46,950	19.59	23.9	9358	312	1643	174	1.03	8865
100	sprinkler	44,770	19.23	23.5	9031	351	1770	225	1.17	8483
125	sprinkler	45,740	19.24	25.3	9735	360	1730	227	1.16	9149
150	sprinkler	45,500	19.15	25.0	9586	346	1608	230	1.11	9035
175	sprinkler	45,130	19.08	24.2	9235	359	1654	228	1.13	8686
200	sprinkler	41,380	18.83	24.0	9044	386	1791	242	1.22	8459
LSD 5%		NS	0.43	1.8	NS	67	86	44	0.11	NS

Stand, yield, and quality of sugarbeets grown under flood and sprinkler irrigation with six rates of available N, 2003-2005.

available N to 4 ft, lb/ac	Irrigation	Harvest Stand, plnts/ac	Percent sucrose	Root Yield T/acre	Sucrose Yield, Lb/acre	Na ppm	K ppm	Amino-N ppm	sucrose loss to molasses	Extract- able Sucrose lb/acre
*	flood	32,630	19.26	26.3	10,100	259	1628	150	0.96	9,597
100	flood	32,310	19.29	26.9	10,370	254	1628	165	0.98	9,846
125	flood	33,800	19.41	27.8	10,770	268	1591	175	0.99	10,220
150	flood	32,430	19.22	27.9	10,720	283	1639	189	1.03	10,140
175	flood	32,070	19.14	28.4	10,860	261	1645	199	1.04	10,270
200	flood	33,070	18.93	28.2	10,700	303	1682	198	1.07	10,100
LSD 5%		NS	0.35	1.3	532	NS	73	26	0.06	518
*	sprinkler	37,430	19.69	27.6	10,860	284	1654	178	1.02	10,290
100	sprinkler	37,470	19.19	28.7	10,980	317	1791	227	1.16	10,310
125	sprinkler	38,880	19.19	29.7	11,410	317	1765	227	1.15	10,720
150	sprinkler	37,470	19.10	29.2	11,160	327	1705	239