Runoff Weed Seed, Sediment, Infiltration and Weed Establishment as Affected by PAM in Furrow-Irrigated Corn
Table 1.   1997 & 1998 Season Totals for Hydraulic Parameters
Treatments Runoff (mm) Infiltration (mm) Sediment Loss (kg ha-1) Advance Time (min)
PAM Herbicide 1997 1998 1997 1998 1997 1998 1997 1998
Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD
No PAM Dual 146 14 119 4 122 16 180 4 13180 4982 5060 379 46 17 88 48
Eradicane 140 4 137 7 127 3 162 7 10134 3094 5663 3731 46 17 86 39
None 129 10 128 11 139 11 172 11 4892 2346 4759 230 54 14 76 29
Average 139 12 128 10 129 12 172 10 9402 4812 5161 1920 49 16 83 38
NRCS STD Dual 139 17 97 14 129 17 204 13 2314 545 638 294 56 20 136 102
Eradicane 137 5 99 20 131 4 201 20 1719 347 631 628 60 13 135 101
None 115 11 98 23 154 11 202 22 1203 359 526 203 61 21 133 91
Average 130 16 98 17 138 16 202 16 1745 607 598 365 59 18 135 95
Patch Dual 128 18 99 27 141 19 201 27 1210 337 409 134 60 31 138 109
Eradicane 131 5 94 22 138 5 206 22 1184 213 425 277 59 19 139 105
None 129 8 102 25 139 8 199 25 861 255 1017 713 55 27 108 70
Average 129 10 98 22 139 11 202 22 1085 290 617 491 58 25 128 94
Average Dual 138 17 105 19 131 17 195 19 5568 6256 2036 2284 54 24 121 91
Eradicane 136 6 110 25 132 6 190 26 4346 4619 2239 3194 55 17 120 88
None 124 11 109 23 144 12 191 23 2318 2274 2101 2043 57 21 106 70
Table 1.   1997 & 1998 Season Totals for Hydraulic Parameters

In both 1997 and 1998 PAM treatment generally reduced cumulative seasonal runoff and sediment loss and increased water advance time and infiltration.  These results parallel findings of numerous previous papers.  Sediment loss reductions for the NRCS standard and patch application methods were 81% and 88% respectively in 1997 and both 88% in 1998.

Herbicide treatment increased cumulative seasonal runoff and sediment loss in 1997 but not in 1998.  There was little effect of herbicide treatment on advance time in 1997, but a lengthening of advance time in 1998 compared to controls.  Herbicide treatment increased infiltration in 1997 but had little if any effect in 1998.

Herbicide effects on runoff, infiltration, sediment loss and advance time in 1997 were as expected, with weedy no-herbicide furrows acting as a vegetative mulch.  Results in 1998 may relate to delayed stand establishment and poorer weed control by herbicides caused by a cool wet spring.
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