Economics of spring wheat production systems using conventional tillage management in the Brown soil zone – Revisited

Abstract

Producers in the semiarid Brown soil zone of the Canadian Prairies have historically used fallow (F)-based cropping systems with mechanical tillage methods to produce spring wheat (Triticum aestivum L.) (W). However, in the past two decades government policies and programs have changed, as have cropping practices, market opportunities, and weather patterns. This study re-examines the economic merits of these conventional cropping systems under today’s conditions in regard to the optimal cropping frequency, value of applying N and P fertilizer at soil test rates, and the possible advantage of replacing monoculture wheat with lentil (Lens culinaris Medikus) (Lent) or flax (Linum usitatissimum L.) (Flx) grown in mixed rotations. The analysis draws on data from a long-term crop rotation experiment that was established in 1967 on an Orthic Brown Chernozem at the Semiarid Prairie Agricultural Research Centre at Swift Current, Saskatchewan. All cropping systems were managed using conventional tillage practices, which attempted to conserve as much surface crop residue as possible (i.e., stubble mulch tillage techniques were used). The findings for 1985–2002, a period characterized by above normal precipitation, were compared with those reported previously for the 1967–1984 period when growing conditions were less favorable but more typical for this area. Net returns during 1985–2002 were highest for W-Lent ($93 ha-1 yr-1) and lowest for F-Flx-W ($38 ha-1 yr-1). Net returns for well-fertilized F-W, F-W-W, F-W-W-W-W-W, and Cont W during this same period were similar, averaging about $52 ha-1 yr-1 or 44% less than for W-Lent. These results contrast with those reported for the previous 18-yr period when F-W and F- W-W generally produced higher net returns than Cont W. Within the F-W-W systems, the application of both N and P fertilizer increased the 18-yr (1985–2002) mean net returns by $18 ha-1 yr-1 compared with application of N only, and by $32 ha-1 yr-1 compared with application of P only. For Cont W the application of N and P fertilizer increased the mean net returns by $71 ha-1 yr-1 compared with application of P only. These economic benefits from N and P fertilization were much higher than those reported in 1967–1984 due to the more humid growing conditions and the increased rate of N fertilizer prescribed by the soil testing lab since 1991. Further, our findings showed that only if producers were highly risk averse, do not subscribe to all-risk crop insurance , or if the price for wheat was high or price for lentil low, would the monoculture wheat systems be preferred to W-Lent. However, producers who are highly risk averse would still opt for the cropping systems that included some summerfallow. Our findings support the recent trends in land use practices by area producers towards more diversified and intensive cropping systems which are less reliant on frequent fallowing. Key words: Crop rotations, wheat, lentil, flax, summerfallow, production costs, net returns, income variability

Diversifying crop rotations with pulses enhances system productivity

“…The inclusion of annual pulses in farming systems, either as a green manure 48,49 or grain crop 50 , has been shown to improve soil physical, chemical, and biological properties 51 , reduce soil degradation 38 , and enhance environmental sustainability 6 . Positive rotational effects of pulses to subsequent cereal or oilseed crops have been well documented in Mediterranean-type climates 52 .…”

“…However, it is not known whether diversifying summerfallow systems with pulses is effective and productive in the northern latitude areas where water is scarce and the growing season is short (95 to 125 days) 25 . Our proposal for diversifying summerfallow systems with short-season pulses is largely based on the latest research on pulses: (a) pulse plants in the northern latitudes have a shallow rooting depth 26 with approximately 77-85% of the roots being located in the 0-0.4 m soil depth 27 , which allows pulse crops to use water mainly from the top 0.6 m soil layer, leaving water in the deeper soil layers (below 0.6 cm) 28 for use by deeper-rooted crops that are grown the following year 29 ; (b) dry pea and lentil, the two main annual pulses grown in the semiarid northern Great Plains, use 15-35% less water than cereal or oilseed crops, thereby enhancing water use efficiency 30 ; (c) pulses are typically harvested several weeks earlier than cereal or oilseed crops, leaving a longer postharvest period during which soil water can accumulate prior to planting crops the following spring 31 ; (d) the inclusion of pulse crops in the rotation can increase crop yields, decrease inputs of inorganic N fertilizer 32 , and enhance N use efficiency 33 ; and finally (e) long-term studies have shown that crop diversification with pulses and oilseed can improve overall farming sustainability 6 . The central hypothesis of the present study is that diversifying cropping systems with pulse crops can improve the attributes of soil water conservation and soil N benefits and increase total grain production.…”

“…, central Africa 5 , and the northern Great Plains of North America 6 . To tackle these challenges, many approaches have been employed, but summerfallow has been historically used as one of the mainstream farming practices in these dry areas.…”

Thirty-seven years of soil nitrogen and phosphorus fertility management shapes the structure and function of the soil microbial community in a Brown Chernozem

“…The abundance of individual PLFAs was expressed as microgram PLFA per gram dry soil. Amounts were derived from the relative area Table 1 Cumulative amounts of residues, and mineral N and P applied on the experimental plots over 37 years, with cumulative amounts of N and P exported from the field through harvests over 37 years Source: Hamel et al 2006;Zentner et al 2007;unpublished. Differences between N and P inputs and outputs (N and P balance) are also given a Number in brackets are standard deviation of the mean. (N=6).…”

Effect of crop rotation, fertilizer and tillage management on spring wheat grain yield and N and P content in a thin Black Chernozem: A long-term study

“…Mots clé s: Triticum aestivum L., jache`re, lixiviation, le´gumineuses, bilan N et P The long-term influence of fertilizers on crop production in the northern Great Plains has been researched in many studies (Zentner et al 1986;Campbell et al 1990Campbell et al , 2005. Most studies have demonstrated the need for, and benefit of, applying adequate fertilizers to achieve optimum economic returns (Campbell et al 1990;Zentner et al 2007).…”