Expected Number Of Days To Harvest Summer Crops In Kansas

 

Weather and workday probabilities vary over time and across Kansas. Knowledge of workday probabilities and the number of expected workable days to conduct fieldwork impacts crop choice and machinery investment decisions.

 

Using the “most active” dates to harvest Kansas crops as estimated from USDA-NASS weekly Crop Progress and Condition Reports (Tables 1 - 4), the number of days suitable during the most active harvest dates from 1980 to 2015 were graphed for corn, soybean, and grain sorghum for each Kansas crop reporting district (see Figure 1 for districts). The “most active” dates are defined as between the 20th and 80th percentile for the 5-year average from 2011 to 2015. When two or more harvesting periods overlap, crop acreage competes for field equipment (see Figure 2). It should be noted that these dates are not necessarily the best timing for highest yields, but when farmers have been observed to actively conduct these field operations.

 

In addition, the most active harvest dates for the three summer crops overlap. They do not start at the same time, but all end in mid-November (Fig. 2). The number of days suitable for harvesting summer row crops based on historical observations for all crop reporting districts are presented in this article. Each crop has a separate section and set of histograms for number of days suitable for harvest.

 

 

 

Most active progress is defined as between the 20th to 80th percentile.

 

 

The corn harvesting season in Kansas extends over three months, beginning at the end of July and extending to mid-November (Fig. 3). Statewide, the period of most active corn harvest dates is September 13 through October 18 (Table 1, see Fig. 3 for graphical representation of the 20th and 80th percentile corresponding to September 13 and October 18). However, each crop reporting district has different typical harvest dates (Table 2). Using the most active harvest dates by crop reporting district, the distribution of the number of days suitable during that time period are graphed in histograms in Figure 4. Most active corn harvest starts as early as August 9 in southeast Kansas and as late as September 27 in northwest Kansas. The Southeast District appears to have fewer days suitable for corn harvest than the other districts but it should be noted that corn harvesting had already begun before crop progress data were reported each year. The most active corn harvesting dates end as early as August 23 in southeast Kansas and as late as October 25 in northeast, northwest, west central, and north central Kansas.

 

 

Most active progress is defined as between the 20th to 80th percentile.

 

Each crop reporting district had a different number of days suitable for harvesting corn during the period of most active harvest dates (Fig. 4). All the crop reporting districts have had at least 10 days suitable for corn harvest each year during the last 35 years, except for the southeast. The Southeast District has a more peaked distribution, with higher frequency from 18 to 22 days suitable. On the opposite side but with a similar distribution is the South Central District, with high frequency of days suitable to harvest of around 50 days.

 

 

 

In Kansas, soybean harvest starts approximately six weeks after the beginning of corn harvest. The most active soybean harvest dates are between October 4 and November 1 (Table 1; Fig. 5 for graphical representation of the 20th and 80th percentile corresponding to most active harvest dates), however each crop reporting district has specific dates (Table 3). The most active harvest dates for soybean start as early as October 4 for most of Kansas and as late as October 18 in southeast Kansas, related to late planting time for this area of the state. The most active soybean harvest dates end as early as October 18 to November 15.

 

Most active progress is defined as between the 20th to 80th percentile.

 

The Southeast District has the most variability in the number of suitable days, with values from 6 to 32 days in a 5-week period. The Central, North Central, Northeast, and Central Districts have approximately bell-shaped distribution, concentrated between 10 and 25 suitable days, indicating possible stable weather conditions from year to year during the harvesting season. The Northwest District peaks around 15-20 suitable days, with a low frequency related to values lower than 10 days (Fig. 6).

 

 

The grain sorghum harvest dates in Kansas are more similar to soybean than corn harvest dates (Fig. 7). The period of most active harvest dates for grain sorghum is between October 11 and November 8 (Table 1 and Fig. 7 for graphical representation of the 20th and 80th percentile corresponding), however each crop reporting district may differ (Table 4). The most active grain sorghum harvesting dates began as early as September 20 (southeast Kansas) and as late as October 18 in the North Central and Northeast Districts. The most active harvest dates in Kansas end as early as November 1 and as late as November 15 for grain sorghum. 

 

Most active progress is defined as between the 20th to 80th percentile.

 

All the crop reporting districts had at least 10 suitable days for harvesting grain sorghum during the most active days (Fig. 8). For the East Central and Southeast Districts the number of suitable days ranges widely from 10 to 45. A more concentrated distribution of suitable days (10 to 30) for harvesting was observed in the Northwest, West Central, and North Central Districts.

 

 

Using historical observed harvest data provides an indication of the expected number of days suitable for harvest. These data empower farmers in making equipment-sizing decisions for a given combination of crops being produced across the farm. We are grateful to USDA-NASS Northern Plains Region Field Office for providing days suitable for fieldwork data for all Crop Reporting Districts.