Reduced-and no-tillage seedbed preparation methods coupled with broadcast P applications lead to an accumulation of available P in the surface 0-to 5-cm soil layer and a depletion of available P deeper in the profile. A 3-yr study determined the effects of tillage and fertilizer P management on P uptake and grain yield for P-stratified soils. Tillage practices were moldboard plow (once at the start of the study followed by reduced tillage), reduced tillage (disk followed by field cultivation), and no-tillage. Four P management methods were imposed: (i) no P; (ii) 20 kg P ha 21 applied as a surface broadcast; (iii) 20 kg ha 21 applied as a banded starter, 5 cm to the side and 5 cm below the seed; or (iv) 20 kg ha 21 applied in a deep placed band, 13 to 15 cm on 0.7-m centers. The one-time moldboard plowing produced higher early season dry matter yields for corn (Zea mays L.), wheat (Triticum aestivum L.), and soybean [Glycine max (L.) Merr.] compared with the no-tillage system, but tillage effects on final grain yield were inconsistent. Subsurface placement of P generally increased P uptake and grain yield of corn and sorghum [Sorghum bicolor (L.) Moench], but had little effect on grain yield of soybean. Results indicate that subsurface applications of P fertilizers should be considered if soil test P is highly stratified within the surface 0-to 15-cm layer and the 15-cm composite is medium or below for available P.

Strip‐till is an alternative conservation tillage system that may overcome the yield depression often seen with corn (Zea mays L.) grown with no‐till on the claypan soils of the eastern Great Plains. The objective of this research was to determine the effect of conservation tillage systems and fertilizer N‐P management on short‐season corn. Continuous corn yields with no‐till, strip‐till in the fall, or strip‐till in the spring declined with year compared with corn grown with reduced tillage. By the third year, corn yields with reduced tillage exceeded 45 bu/acre more than with the other tillage systems. In part, this can be attributed to a reduced plant stand in no‐till and strip‐till systems. Average corn yield was about 10% greater when N‐P applications were made in the spring than in the fall. Similarly, knife (subsurface band) applications of N‐P resulted in about 12% greater yield than dribble (surface band). Yield differences due to fertilizer timing or placement were related to similar increases in the number of kernels per ear. Strip‐till done either in the fall or spring for corn grown in claypan soil did not improve yield compared with no‐till and may be less than yields with reduced tillage. Knife applications of N‐P fertilizer done in the spring may help mitigate this deficit if the producer prefers the conservation aspects of strip‐ or no‐till systems.

SummaryA total of 135 steers grazed high-endophyte tall fescue pasture interseeded with either lespedeza, red clover, or ladino clover during 1995, 1996, and 1997. Legume cover, forage dry matter production, grazing steer performance, and subsequent feedlot performance were measured. Legume treatment caused no differences in forage availability. Grazing gains corresponded to the amount of legume coverage present. Results of this study indicate that interseeding high endophyte fescue pastures with ladino clover produced higher stocker gains during the grazing phase than interseeding with lespedeza or red clover. Legume treatment had no effect on subsequent finishing gains.

SummaryA total of 135 steers grazed high-endophyte tall fescue pasture interseeded with either lespedeza, red clover, or ladino clover during 1995, 1996, and 1997. Legume cover, forage dry matter production, grazing steer performance, and subsequent feedlot performance were measured. Legume treatment caused no differences in forage availability. Grazing gains corresponded to the amount of legume coverage present. Results of this study indicate that interseeding high endophyte fescue pastures with ladino clover produced higher stocker gains during the grazing phase than interseeding with lespedeza or red clover. Legume treatment had no effect on subsequent finishing gains.

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