Soil Water Depletion and Recharge under Ten Crop Species and Applications to the Principles of Dynamic Cropping Systems
- Stephen D. Merrill *,
- Donald L. Tanaka,
- Joseph M. Krupinsky,
- Mark A. Liebig and
- Jonathan D. Hanson
Dynamic cropping systems principles require that farmers consider climatic, market, and ecological factors on an annual basis in making crop choices. Our objectives were to determine variability of seasonal soil water depletion (SWD) and spring soil water recharge (SWR) among crops and to apply results to dynamic cropping systems practice. A 10-species crop sequence project was conducted under no-tillage on silt loam Haplustoll soils in North Dakota. Mid-May to mid-September SWD and following April SWR were determined from 2002 to 2005 by neutron moisture meter to the 1.8-m depth. Crops studied and average SWD amounts (cm) were: sunflower (Helianthus annuus L.), 13.5; corn (Zea mays L.), 12.6; sorghum [Sorghum bicolor (L.) Moench], 11.0; spring wheat (Triticum aestivum L.), 10.6; canola (Brassica napus L.), 10.0; millet (Panicum miliaceum L.), 9.6; buckwheat (Fagopyrum esculentum Moench), 9.4; chickpea (Cicer arietinum L.), 8.5; lentil (Lens culinaris Medik), 8.1; and dry pea (Pisum sativum L.), 5.0, with highest and lowest being 29 and 11% of average May soil water, 46 cm. Because the period of the experiment was relatively dry, recharge was less than depletion. Spring soil water was 10 cm greater following pea than following sunflower. Ranking of crops for water storage roughly followed reverse SWD rank, with several exceptions, notably wheat, which had greater water from snow capture. Lower soil water following crops such as sunflower and corn was linked to negative crop sequential effects in this project. Choosing to seed a lower water-using crop in the spring after the occurrence of below-average SWR on land that had a higher water-using crop the previous season illustrates an application of information reported here along with the principles of dynamic cropping systems.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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