Oakes Irrigation Research
Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Voice: (701) 742-2189, FAX: (701)
742-2700, email: rgreenla@ndsuext.nodak.edu
PUMPKIN COVER CROP AND LIVING MULCH STUDY
Richard Greenland
Pumpkins are planted in wide rows, leaving large areas of bare ground between rows. In current pumpkin production, the between-row area is usually cultivated early in the season, before the pumpkin plants begin to run, to control weeds. This exposes the soil to erosion and also reduces soil organic matter. Later in the season hand weeding is used to control weeds. After harvest of pumpkins, little residue is left to protect the soil and it is usually too late in the season for cover crop establishment. Cover crops and living mulches planted between the pumpkin rows could prevent soil erosion and increase soil organic matter, but if they compete too much with the pumpkins then pumpkin yield could be reduced. In this study a barley cover crop was planted in early spring, leaving unplanted strips, 3.5 ft wide, for planting pumpkins in mid- to late-May. When the barley headed, it was flailed and a living mulch (hairy vetch, rye, soybean, and/or corn) was planted between the pumpkin rows. Additional treatments included in the study were herbicide vs. cultivation and high vs. low flailing of the barley cover crop. Our objective was to find a cover crop/living mulch management system that would protect the soil, help control weeds, but not compete with the pumpkins enough to reduce pumpkin yield. Last year the effect of the living mulch/cover crop on pumpkin and on total dry matter at the end of the season was determined. (Click here for results) This year we planted the entire study to sweetcorn to see if there was a carryover effect from the cover crop treatments applied to the pumpkins.
MATERIALS AND METHODS
Soil: |
Maddock sandy loam; pH=6.9; 1.9% organic matter; soil-P was very high, and soil-K was high; soil-S was low. |
Previous crops: |
2003 - pumpkin; 2002 - field corn and popcorn; 2001 - cabbage, onion, potato and pumpkin. |
Seedbed preparation: |
Disk on April 13. Multiweeded (field cultivated) on May 10 to incorporate fertilizer. |
Planting: |
‘Honey Select’ sweetcorn was planted on May 13 in 30-inch rows at 30,000 seeds/acre. |
Plots: |
17 ft long by 17 ft (about 7 rows) wide. There were four reps. |
Fertilizer: |
On April 15 broadcast 20 lbs N/acre and 24 lbs S/acre as 20-0-0-24. Applied 50 lbs N/acre on May 10 as 28-0-0, and 100 lbs N/acre on June 23 as 28-0-0 + Agrotain (2.4 qt/ton of N). |
Irrigation: |
Overhead sprinkler irrigation as needed. |
Pest control: |
Sprayed Outlook + AAtrex (1 pt/acre + 0.5 lb ai/acre on May 14), Aim + NIS (0.5 oz/acre + 0.25% v/v on June 24) and Dipel (2 lb/acre on July 7 and July 15). |
Harvest: |
Hand harvested two center rows on August 20 to 26 |
Weed control and yield of sweetcorn were not affected by the living mulch/cover crop treatments.
Go to top of pumpkin cover crop study
Table 64. Effects of cover crops/living mulches used in pumpkins in 2003 on weed growth and on sweetcorn yield in 2004.
Treatment |
Early stand |
Weed ratings July 26 |
Marketable sweetcorn |
|||||
Rrpw1 |
Colq1 |
Hns1 |
FT1 |
ears |
yield |
ear size |
||
|
1000s/A |
----------------------- 0 to 102 ----------------------- |
1000s/A |
tons/A |
lbs/ear |
|||
Cover crop/living mulch |
||||||||
No barley, no mulch |
18.1 ab3 |
8.1 |
8.4 |
8.1 |
6.9 |
16.8 |
7.8 |
0.9 |
Barley, no mulch |
16.5 b |
8.6 |
8.8 |
8.2 |
6.3 |
16.0 |
7.4 |
0.9 |
Barley, hairy vetch |
19.5 a |
8.6 |
8.8 |
8.2 |
6.9 |
18.5 |
8.6 |
0.9 |
Barley, rye |
16.1 b |
8.3 |
8.7 |
8.4 |
7.5 |
16.1 |
7.3 |
0.9 |
Barley, hairy vetch + rye |
17.0 b |
8.4 |
9.0 |
8.0 |
7.3 |
17.9 |
8.2 |
0.9 |
Barley, soybean |
18.0 ab |
8.7 |
8.6 |
8.3 |
5.7 |
16.5 |
7.7 |
0.9 |
Barley, soybean + corn |
19.8 a |
8.5 |
8.7 |
8.3 |
5.9 |
18.0 |
8.3 |
0.9 |
Barley, corn |
17.8 ab |
8.4 |
8.4 |
8.3 |
7.0 |
17.0 |
8.0 |
0.9 |
|
||||||||
Probability |
0.04 |
0.85 |
0.18 |
0.91 |
0.30 |
0.59 |
0.74 |
0.94 |
|
||||||||
Cultivation vs. herbicide |
||||||||
Cultivation |
17.5 |
8.6 |
8.5 |
8.2 |
6.2 |
16.5 |
7.6 |
0.9 |
Herbicide |
18.2 |
8.3 |
8.8 |
8.3 |
7.2 |
17.7 |
8.2 |
0.9 |
|
||||||||
Probability |
0.26 |
0.26 |
0.38 |
0.74 |
0.22 |
0.22 |
0.14 |
0.84 |
C.V. (%) |
13 |
7 |
6 |
6 |
17 |
14 |
14 |
6 |
|
||||||||
Barley flail height |
||||||||
High |
17.5 |
8.6 |
8.7 |
8.2 |
6.6 |
17.2 |
8.0 |
0.9 |
Low |
18.1 |
8.4 |
8.8 |
8.3 |
6.7 |
17.1 |
7.8 |
0.9 |
|
||||||||
Probability |
0.20 |
0.35 |
0.39 |
0.50 |
0.74 |
0.91 |
0.62 |
0.18 |
C.V. (%) |
13 |
7 |
5 |
5 |
13 |
13 |
12 |
5 |
1Weed identification: Rrpw - redroot pigweed; Colq - common lambsquarters; Hns - hairy nightshade; FT - yellow and green foxtail.
2Ratings from 0 to 10: 0 = no weed control; 10 = no weeds present.
3Values in this column followed by the same letter are not significantly different at the 0.05 level. There were no statistically significant
differences between values in any other column.
Go to top of pumpkin cover crop study
Go to Oakes Irrigation Research Site Cover Crop Study page
Go to Oakes Irrigation Research Site 2004 annual report