Corn Yield Response to Tillage with Furrow Irrigation

Abstract

Conservation tillage techniques have gained widespread, but not universal, use in irrigated corn (Zea mays L.) production. This study was conducted to evaluate yield impacts associated with conservation tillage methods when compared with conventional techniques in a replicated field experiment for 17 consecutive years in Nebraska (1976–1992). Six tillage treatments were imposed on continuous corn production and replicated three times. Tillage treatments ranged from traditional (disk and surface plant) to no‐till (slot plant on existing ridge). Post‐plant operations were uniformly applied to accommodate furrow irrigation. Over the life of the project the conservation tillage treatments (ridge till, rotary till, and slot plant) had a 4 bu/acre increase in grain yield over the conventional treatments (those having chisel, disk, or lister operations). The advantage of the conservation tillage systems was amplified by corresponding lower production costs. The rotary, ridge, and slot tillage systems had $7.72, $14.22, and $16.22/acre lower annual tillage and herbicide costs (1990 dollars), respectively, than the conventional tillage system with a disking operation. The conservation tillage treatments significantly lowered stalk rot and residual spring soil nitrate N concentrations. Other comparisons showing significant differences were list vs. chisel and disk for harvest population and soil potassium concentrations, and ridge vs. rotary for harvest population. None of the other comparisons tested had significant differences for grain yield or other soil parameters. Overall, this study indicates that conservation tillage on irrigated continuous‐corn is advantageous over conventional methods. Research Question Are furrow‐irrigated corn yields increased with conservation tillage? Furrow irrigation and conservation tillage techniques are both common to irrigated agriculture in the U.S. Corn Belt. This study evaluated corn yield for six different tillage systems over 17 yr in a furrow irrigated field trial in south central Nebraska. Literature Summary Long term field studies of the relationship between tillage activities and corn yield show mixed results. Some studies show that corn yield increased when less intensive tillage practices were used. Other studies showed no effect or even a decrease in corn yield with conservation tillage. In these other studies there are many factors involved—soil temperatures, weed control, disease problems, or seed placement, for example. Much of the information available concerning alternative tillage and corn yield is from nonirrigated studies where year‐to‐year climate plays a larger role. Study Description Corn yield was collected in a field study for 17 yr (1976–1992) at Clay Center, NE. The field was furrow irrigated. The tillage treatments evaluated were: conventional tillage (disk, surface plant, and ridge) conventional tillage with a chisel operation after shredding conventional tillage with a lister attachment on the planter ridge tillage rotary tillage slot planting Herbicide ...

Economics of Irrigated Continuous Corn under Conventional‐Till and No‐Till in Northern Colorado

“…While Cahoon et al (1999) also reported increases in economic returns when reducing tillage on irrigated continuous corn, their findings were in part due to observed yield increases, in contrast to our results. Our results are similar to those reported by Tew et al (1986), however their results showed economic benefits for a minimum tillage system compared to CT without including reductions in machinery ownership costs.…”

“…However, gross margins for minimum tillage were less than for a tillage system which created alternating 76‐cm tilled strips. Cahoon et al (1999) reported that use of conservation tillage on irrigated continuous corn increased corn grain yields and economic returns compared to conventional systems. Similarly, Smart and Bradford (1999) reported higher economic returns for corn in conservation tillage systems compared to CT systems due to greater yields in dry years and lower production costs.…”

Tillage and Nitrogen Application Methodology Impacts on Corn Grain Yield

“…The effects of these different tillage practices on yield have been evaluated in different regions of the U.S. (Bordovsky et al, 1998;Mullins et al, 1998;Wesley et al, 1988) and throughout the world (Fischer et al, 2002;Ghuman and Sur, 2001;Grant and Lafond, 1994;Iqbal et al, 2005;Lal, 1976), for different soil types and for different crops (Tsuji et al, 2006) and rotations (Dick and Van Doren, 1985;Wilhelm and Wortmann, 2004). The general development in most of these systems has been an increase in positive impact or decrease in the negative impact of no tillage on grain yield (Cahoon et al, 1999;Dick et al, 1991;Edwards et al, 1988) and accumulation of soil organic matter in the soil surface (Grant and Lafon, 1994;Dick, 1983;Hussain et al, 1999;Karlen et al, 1989;Rhoton et al, 1993). Eight years of no-till on a Grenada silt loam soil for different crops was evaluated to determine the time factor required to improve soil properties under no-till and this was determined to be four years (Rhoton, 2000).…”

Nitrogen and Tillage Effects on Irrigated Continuous Corn Yields

“…Research from more humid areas suggests that the delay in early crop development with NT had no detrimental effect on final crop yield (Mehdi et al, 1999;Wolfe and Eckert, 1999). Cahoon et al (1999) reported higher yields and greater economic returns when using conservation tillage on irrigated continuous corn. Smart and Bradford (1999) also reported greater economic returns from NT than from a CT corn production system.…”

“…Limited information is available on use of NT systems on irrigated lands in the semiarid central Great Plains (Cahoon et al, 1999;Sims et al, 1998). Data available from the more humid Western Corn Belt and eastern Nebraska suggest that NT systems may produce lower grain yields than CT systems (Wilhelm and Wortmann, 2004;Randall, 2002, 2004;Sims et al, 1998).…”