Research Article
Corn Hybrid Response to Water Management Practices on Claypan Soil
Table 1
Soil organic matter and pH from 0 to 15 cm and corn management practices in 2008, 2009, and 2010.
| Soil and site management practices† | 2008 | 2009 | 2010 |
| Soil test values | | | | Soil organic matter (g kg−1) | 18 ± 1‡ | 21 ± 1 | 22 ± 1 | pH (0.01M CaCl2) | 6.6 ± 0.05 | 6.9 ± 0.1 | 6.7 ± 0.3 |
| Fertilizer (N-P2O5-K2O kg ha−1) | | | | 34-90-180 | 26 Nov. 2007 | NA | NA | 200-0-0 as anhydrous ammonia | 1 May | 8 Apr. | 27 May | Tillage (date) | Chisel plow (25 Nov. 2007) | | | Tilloll§ (2 May) | Tilloll (23 Apr.) | Tilloll (19 and 20 May) | Planting date | 5 May | 24 Apr. | 28 May | Nondrained, nonirrigated delayed planting | | 12 May | |
| Weed control¶ | | | | Timing, date | EPOST, 29 May | EPOST, 21 May | PRE, 30 May | Herbicide (rate) | Glyphosate (0.84 kg ae ha−1) + DAS (20 g L−1) + premixture of atrazine + S-metolachlor + mesotrione (3.3 kg ai ha−1) | glyphosate (0.84 kg ae ha−1) + premixture of atrazine + dimethenamid-P (3.5 kg ai ha−1) | Saflufenacil (0.025 kg ai ha−1) + glyphosate (0.84 kg ae ha−1) | Timing, date | | POST, 25 June | POST, 22 June | Herbicide (rate) | | Glyphosate (1.2 kg ae ha−1) + DAS (20 g L−1) | Premixture of acetochlor + atrazine (5 kg ai ha−1) | Timing, date | | | LPOST, 29 June | Herbicide (rate) | | | Glyphosate (0.84 kg ae ha−1) + DAS (20 g L−1) |
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†Abbreviations: EPOST: early postemergence; DAS: diammonium sulfate; LPOST: late postemergence; NA: none applied; PRE: preemergence. ‡Standard deviation. §Tilloll 875, Marysville, KS. ¶Herbicide chemical names: acetochlor: (2-chloro-2′-methyl-6′-ethyl-N-ethoxymethylacetanilide); atrazine: (6-chloro-N-ethyl--(1-methylethyl)-1,3,5-triazine-2,4-diamine); dimethenamid-P: (2-chloro-N-[(1-methyl-2-methoxy)ethyl]-N-(2,4-dimethyl-thien-3-yl)-acetamide); glyphosate: (N-(phosphonomethyl)glycine); mesotrione: (2-[4-(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione); S-metolachlor: (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide); saflufenacil: (-[2-chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)benzoyl]-N-isopropyl-N-methylsulfamide).
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