Field Pea and Chickpea Germination and Yield as Affected by Tillage

Two photos of chickpeas in the field, one grown in no-till (L) and one grown with tillage (R) at Grant in 2018
Figure 1. Comparison of chickpeas grown in no-till (L) and tillage (R) at Grant in 2018

Field Pea and Chickpea Germination and Yield as Affected by Tillage

Field peas and chickpeas are pulse crops often grown as a fallow replacement in western Nebraska dryland cropping systems (wheat-fallow or wheat-corn-fallow). Although the most dominant cropping system is no-till, several farmers observed that tillage prior to planting produced better field pea yields. Possible reasons for increased yields with tillage are often attributed to

  • earlier and more uniform emergence and canopy development,
  • better weed suppression,
  • extended flowering (reproductive) periods, and
  • uniform maturity and dry down at harvest.

A field study was undertaken to evaluate the effects of tillage on germination patterns and grain yield of yellow field peas and chickpeas.

Trial Summary

The study was conducted at the Henry J. Stumpf International Wheat Research Center at Grant, Nebr. during the 2018-2019 growing seasons. The predominant soil type in the study area was Kuma silt loam. In 2018 field peas and chickpeas were grown behind corn; in 2019 crops were grown behind winter wheat. Both years tillage was performed in tillage blocks using a Krause 32-foot tandem disk (heavy disk). The study area was sprayed with a PRE herbicide (Spartan Elite®) within a week before planting. At planting, chickpea seed was treated with seed fungicide (Obvious®) and both field pea and chickpea seed were inoculated with full rates of liquid and peat inoculants (Cell-Ttech®).

The field pea variety Durwood was planted on March 14 and March 29 in 2018 and 2019, respectively. Field pea seeding rate was 350,000 live seeds per acre and planting was performed using a 20-foot Crustbuster no-till box drill with a 7.5-inch row spacing. Two chickpea varieties, Frontier and Orion, were planted on March 23 and March 29 in 2018 and 2019, respectively. The seeding rate for chickpeas was 220,000 live seeds per acre in 15-inch rows and planting was performed using two passes with an eight-row John Deere® planter. Field peas were harvested on July 20 in 2018 and July 25 in 2019. Chickpeas were desiccated using generic paraquat seven days before being harvested on August 17 in 2018 and August 20 in 2019.

Graph of monthly precipitation in 2018, 2019 and 30-year average
Figure 2. Total precipitation, average minimum temperatures, and average maximum temperatures during the 2018 and 2019 pulse crop-growing seasons at Grant, Nebr. and the 30-year averages for the region.

Germination

Slow germination of both field peas and chickpeas can be attributed to early planting (mid- to late March) in combination with cool springs in both 2018 and 2019 (Figure 2). Although it took 28-46 days to achieve 10% germination (late-April), it took 7-14 days for field peas and chickpeas to finish germinating (Figure 3, Table 1).

Tillage had a positive impact on germination. The germination started, progressed, and finished earlier in tillage treatments, regardless of the crop (Table 1; Figure 3). In 2018, field pea germination at 10%, 50%, and 90% occurred 46, 49, and 54 days after planting, respectively; this was 4, 4 and 2 days earlier than the 10%, 50%, and 90% field pea germination in no-till blocks, respectively (Table 1). Similar trends occurred in 2018 chickpeas and in the 2019 growing season.

Compared to tilled fields, no-till planted field peas finished germinating (90% germination) 2 and 9 days later in 2018 and 2019, respectively; germination in no-till chickpeas was delayed by 5 days in 2018 and by 3 days in 2019 (Table 1, Figure 3).

Grain Yield

Tillage either maintained or increased the grain yield of field peas and chickpeas. In 2018, grain yield of field peas was increased by 12 bu/ac while chickpea yield was increased by 6 bu/ac. There was no impact of tillage on grain yield in 2019 (Figure 4).

Table 1. Effects of tillage treatments on pulse crop germination, days after planting (DAP)*, and date at 10%, 50%, and 90% germination.
Pulse Crop
Year
Tillage 10% germination   50% germination   90% germination
    DAP Date     DAP Date     DAP Date
Field peas
2018
no-till 46 29-Apr-18 49 2-May-18 54 7-May-18
tillage 42 25-Apr-18 45 28-Apr-18 52 5-May-18
Chickpeas
2018
no-till 37 29-Apr-18 41 3-May-18 47 9-May-18
tillage 36 28-Apr-18 38 30-Apr-18 42 4-May-18
Field peas
2019
no-till 27 25-Apr-19 38 6-May-19 48 16-May-19
tillage 25 23-Apr-19 29 27-Apr-19 37 5-May-19
Chickpeas
2019
no-till 32 30-Apr-19 38 6-May-19 49 17-May-19
tillage 28 26-Apr-19 35 3-May-19 46 14-May-19
* Planting dates: Field peas 2018 (March 14), chickpeas 2018 (March 23), field peas and chickpeas 2019 (March 29)

Graphs of germination timing for field peas and chickpeas for 2018 and 2019.
Figure 3. Cumulative germination (%) of field peas and chickpeas as influenced by tillage treatment in 2018 and 2019 growing season at Grant, Nebr. The regression lines are plotted against the day of the year (i.e., Julian day).
Graph of the effects of tillage treatment on yield of chickpeas and field peas
Figure 4. Effects of tillage treatment on grain yield of field peas and chickpeas in field experiments conducted at Grant, Nebr. during the 2018 and 2019 growing seasons. Different letters refer to statistically significant differences between the treatments.

Grain Yield

Tillage either maintained or increased the grain yield of field peas and chickpeas. In 2018, grain yield of field peas was increased by 12 bu/ac while chickpea yield was increased by 6 bu/ac. There was no impact of tillage on grain yield in 2019 (Figure 4).

Recommendation

We caution farmers to use tillage as a strategy to increase the grain yield of field peas and chickpeas, especially under dryland conditions of semiarid climates such as southwest Nebraska. Although faster germination can be seen as a benefit, tillage often causes issues with crusting, ponding, and increases soil evaporative and erosion potential. Moreover, tillage increases the production cost without a secure return on the investment.

Planting field peas and chickpeas is often challenging in a heavy crop residue. Lighter tillage (e.g., vertical till) or various field operations such as residue chopping or light residue grazing during the winter months may be more suitable strategies in creating favorable planting conditions for field peas and chickpeas.