Prediction of Nitrogen Status of Sugarbeets by Soil Analysis¹

Abstract

The production of high sugar yielding crops of sugarbeets (Beta vulgaris L.) is highly dependent on available N. Excessive N fertilization is frequently cited as a cause of low sugar containing beets, which has become a problem in todays beet industry. The objective of this study was to evaluate the usefulness of N soil tests to predict N fertilizer requirements for this crop. Fertilizer trials consisting of 4 N rates (0, 70, 140, and 210 kg N/ha) were conducted on 33 farm sites in central and eastern Colorado over a 2‐year period. Soils ranged in texture from sandy loam to clay loam and were generally calcareous at or near the surface having a pH > 7.0. The results show that soil NO3‐N levels measured before planting are useful in estimating the N requirements of the sugarbeet crop. Soil NO3‐N levels were closely correlated with crop yield and sucrose percentage. Regression analysis indicated that yield and recoverable sugar responses to fertilizer N are unlikely when soil NO3‐N levels (0 to 60 cm) are > 130 kg/ha. A linear decrease in sucrose percent resulted from increasing N levels. Soil NO3‐N had a greater effect on sucrose percentage and plant N content than did an equal amount of fertilizer N during both years. An assessment of the NO3‐N content of the soil to at least the 60‐cm depth was found to be an adequate index of soil mineral N availability.

Influence of Sampling Date on Soil Nitrogen Availability Indices

“…Close correlations between soil inorganic N and biological indices were also found by Roberts, Weaver, and Phelps (1980) and Paul and Beauchamp (1993). It seems that the inorganic N in the soil profile not only represents a quantitative value but is also a qualitative index, providing a good indication of the N-mineralization potential of a soil (Giles, Reuss, and Ludwick 1975;Roberts, Weaver, and Phelps 1980). The soil NO 3 -N in the soil profile before sowing has often been used as the basis for fertilizer N recommendations, in particular in the advisory systems of semi-arid regions (Boswell, Meisinger, and Case 1985).…”

“…Soil inorganic N has frequently been found as a good indicator of the N-supply power of soils. Giles, Reuss, and Ludwick (1975) reported that the soil NO 3 -N levels measured before planting were useful in estimating the N requirements of a sugarbeet crop. Close correlations between soil inorganic N and biological indices were also found by Roberts, Weaver, and Phelps (1980) and Paul and Beauchamp (1993).…”

Prediction of nitrogen uptake by sugar beet (Beta vulgarisL.) by scoring organic matter and nitrogen management (N-score), in Hokkaido, Japan

“…, not only because of the large variability in soil N fertility (soil N supply) among fields (Goodlass et al 1996;Konno 2001;Sato et al 2008;, but also because the responses of yield and N uptake to N application rate are quite different, depending on field conditions such as soil type and organic matter application (Hasegawa and Nomura 1973;Giles et al 1975;Imura and Hayasaka 1982;Igarashi and Nakamura 1983;Nishimune 1984;Shinsenji et al 1984;Okumura et al 1989). Hence, considerable efforts have been exerted to develop an effective soil test for evaluating N fertility.…”

“…This technique may be a precise and effective methodology for sugar beet, because sugar beet is also a deep-rooted crop as winter wheat (Suzuki and Shiga 2004). Giles et al (1975) and Bilbao et al (2004) reported that soil nitrate N test was a useful method for accessing N fertilizer rate in sugar beet production, if no organic matter was applied prior to planting sugar beet.…”

Residual Nitrate and Mineralizable Soil Nitrogen in Relation to Nitrogen Uptake by Irrigated Sugarbeets1

“…A MOUNTS of residual soil NO3 reflect management, N fertilization, and irrigation practices and influence the optimal level of N fertilizer needed for sugarbeets, (Beta vulgaris L) (1,2,3,4,5). The remainder of the soil derived N is supplied through mineralization of soil organic N (1, 2, 3, 5, 11).…”