Crop Sequencing to Improve Use of Precipitation and Synergize Crop Growth

Abstract

resources may become inherent to a cropping system, if the system is to be sustainable.Cropping systems will not be sustainable without change. Broad-One problem associated with cropping systems is how scope problems associated with developing sustainable cropping systems are how to choose and sequence crops in cropping systems. Our to choose and sequence crops to develop the inherent objectives were twofold: (i) evaluate impacts of crop sequencing on internal resources of the system while taking advantage precipitation use and (ii) show how crop sequencing can accentuate of external resources such as weather, markets, governsynergistic interactions among crops. Crop-fallow systems that develment programs, and new technology (Tanaka et al., 2002). oped in the Great Plains resulted in precipitation storage efficiencies To better understand and appreciate cropping systems of about 20% in the early 1930s to about 40% in the late 1980s. and the crops used in them, we must consider the evolu-Integrated crop-livestock systems have been developed in the southern tion that crops and cropping systems have gone through. Great Plains to take advantage of bimodal annual precipitation pat-Our goal is to stimulate researchers to think at the systern to produce high quality pigeonpea [Cajanus cajan (L.) Millsp.] tems level when conceptualizing and developing intenforage during the noncrop period between winter wheat (Triticum sive-diverse cropping systems. Our objectives were twoaestivum L.) harvest and seeding. Pigeonpea can be grown after a mid-June winter wheat harvest since pigeonpea uses precipitation received fold: (i) evaluate the impact of crop sequencing on use from wheat harvest to late September and pigeonpea has a root system of precipitation and (ii) show how crop sequencing can that allows it to use soil water below the effective rooting depth of accentuate synergistic interactions among crops in the wheat. In the central Great Plains, water-use efficiency of winter Great Plains.wheat was improved 18 to 56% by including broadleaf crop in a grassbased rotation. Cropping systems in the northern Great Plains tend to be more diverse, and research at Mandan, ND, suggests that seed growth through evapotranspiration, approached 75% for continuous annual cropping systems compared with Published in Agron. J. 97:385-390 (2005). less than 45% for winter wheat-fallow system (Farahani

Crop response to current and previous season applications of phosphorus as affected by crop sequence and tillage

“…The effect may be due to a number of factors, including some degree of allelopathy from canola residue (Haramoto and Gallandt 2005), early-season competition from volunteer canola plants or restriction in mycorrhizal colonization after canola. In a study evaluating sequencing of 10 different crops in North Dakota, Tanaka et al (2005) noted that flax seeded on canola was intermediate in yield in the first year of the study when moisture was 186% of normal, but produced the second lowest yield, after flax seeded on flax, in the second year when precipitation was 104% of normal. In the current study, flax yield was consistently higher after wheat rather than after canola, with the largest difference in yield occurring in 2002, a year with drier than average conditions from May to July and higher than average rainfall in August (http://climate.weatheroffice.ec.gc.ca/climate data accessed 2008 Jul.…”

“…04). Tanaka et al (2005) noted that in the year with average precipitation, the yields of 6 of the 10 crops grown were lowest when the preceding crop was canola, with the effect of crambe (Crambe abyssinica H.) on following crops being similar to that of canola; no explanation was offered for the mechanism of the depressive effect of canola on crop yield. Gubbels and Kenaschuk (1989), working in southern Manitoba, found that flax yields were 9% lower on canola than barley residue but that there was little influence of crop residue when there was no tillage prior to planting.…”

Legume, cropping intensity, and N-fertilization effects on soil attributes and processes from an eight-year-old semiarid wheat system

“…However, negative summer fallow effects have been widely reported since the early twentieth century (Linfield 1902;Atkinson and Nelson 1911;Ford and Krall 1979;Carlyle 1997;Janzen 2001;Tanaka et al 2010) with many associated with SOM decline. Recently, improved soil water storage efficiency in no-till systems has helped to eliminate summer fallow in some regions of the NGP (Tanaka and Anderson 1997;Tanaka et al 2005).…”

Influence of effective microorganisms and green manure on soil properties and productivity of pearl millet and alfalfa grown on sandy loam in Saudi Arabia

“…Other organic materials like rice straw, wheat straw, rice husk and chopped salt grass also improved the physical properties of a saline sodic soil, (Hussain et al, 2001). Increasing organic matter in soil as a result of green manure improved soil structure, increas ed aggregat es stability, enhance infiltration rate, led to higher water-holding capacities and increased water use efficiency (Tanaka et al, 2005;Narayan and Lai, 2006). Using legumes green manure and crop rotation increased the level of Nit rogen, Phosphorus, and potassium in soil especially Nitrogen.…”