Does rolling a bed help or hurt with flextine cultivation efficacy…and why?
Daniel Priddy1 and Daniel Brainard2
1Graduate Research Assistant, and 2Professor, Michigan State University
Take-home points:
- Conventional wisdom suggests that a rolled level bed is valuable for improving flextine cultivation efficacy since it results in more consistent down-pressure and depth.
- Our results demonstrate that rolling a bed also can increase soil surface moisture content and soil penetrometer resistance (crusting) both of which tend to reduce efficacy.
- In field trials we found that the net effect of rolling in several cases was reduced efficacy of flextine cultivation.
Problem
Preparation of fine, level seed beds is often considered essential for successful vegetable crop establishment and subsequent cultivation. While likely true in many cases, excessive attention to bed preparation comes at a cost, both in terms of soil health, and economics. To better understand the tradeoffs associated with bed preparation, growers need to know how bed preparation practices influence the efficacy of cultivation tools.
Approach
We conducted a series of field experiments in which soils were either rototilled, or rototilled and then rolled to create a more level surface prior to planting either sweet corn or snap beans. Prior to mechanically cultivating with a Einbock flextine cultivator, we then took measurements of three characteristics of soil surface: water content (gravimetric measurement from surface layer); micro-penetrometer resistance (force gauge); and surface roughness (LIDAR). We also did pre- and post-cultivation counts of weeds, including both those emerging naturally in the field, and surrogate weeds (red Amaranth and condiment mustard) which we sowed by hand following bed preparation.
Results
Effects of rolling on soil surface conditions. Not surprisingly, we found that rolling the bed, resulted in a more level uniform surface (lower “random roughness” as determined from LIDAR scans). We also found that in several cases, rolling also resulted in higher soil surface moisture and micropenetrometer resistance (force required to break surface).
Effects on flextine efficacy. In several cases, we found significantly greater survival of weeds (both ambient and surrogate), and hence lower efficacy of flextine cultivation, in beds that had been rolled (Figure 1).
Figure 1. Effects of pre-plant rolling on weed survival following Einbock flextine cultivation.
Next Steps
The next step is to conduct regression analysis to better determine which characteristics of soil surface (moisture, crusting or roughness) were most closely associated with flextine efficacy. From a preliminary analysis, we suspect soil moisture is often a more critical characteristic than surface roughness (within limits) in determining success with flextine cultivation.
Within the same experiment, we have also evaluated the effects of pre-plant compost applications on efficacy of flextine cultivation, and will conduct similar soil surface analyses to determine both whether and why compost applications affect weed survival.