Nitrogen, Phosphorus, and Potassium Effects on Grain Sorghum Production and Stalk Rot Following Alfalfa and Birdsfoot Trefoil

Abstract

2 Grain sorghum [Sorghum bicolor (L.)], grown on the often infertile claypan soils of the eastern Great Plains, requires attention to soil fertility. Experimental objectives were to determine the effects of phosphorus (P) and potassium (K) fertility levels, N application, and legume residual on grain sorghum production and stalk rot. Following alfalfa and birdsfoot trefoil, first-year sorghum yield was 7 Mg ha −1 and not affected by N fertilizer. In subsequent years, yield increases due to N were less than 20%. Sorghum yield increased at low P and K rates, especially with nitrogen (N) fertilization and was greater following birdsfoot trefoil than following alfalfa. In 1995 when fertilized with N, lodging and stalk rot severity were increased by P and reduced by K. In 1996, stalk rot severity was reduced by K fertilization. Grain sorghum, grown after legume crops, required minimal levels of P and K, especially when N fertilizer was added.

The potassium paradox: Implications for soil fertility, crop production and human health

“…One of the better known consequences of KCl fertilization, reported in Table 5 for studies with corn 153,201,212,216 , wheat 221 and sorghum (Sorghum bicolor L. Moench) 137 , arises from the antagonistic effect of Cl − on NO 3 − uptake that reduces lodging or stalk rot when susceptible cereal varieties are grown on a soil with high N-supplying power and/or with heavy inputs of fertilizer N, but at the expense of promoting NO 3 − loss through leaching or denitrification. The use of KCl can also have a beneficial effect by increasing the fiber strength (micronaire) of cotton (Gossypium hirsutum L.) grown on soils inherently limited in K reserves [222][223][224]226 , which would be expected considering the lack of a dense rooting system or residue K inputs.…”

Phosphorus and Potassium Application Improves Fodder Yield and Quality of Sorghum in Aridisol under Diverse Climatic Conditions

“…Availability of balanced nutrients improves meristematic and physiological activities [36,[42][43][44]. This resulted in increased resource use efficiency and more dry matter accumulation per unit area/time as well as higher yield.…”

“…Soil application of 80-40 kg P-K ha −1 increased 40% and 44% dry mater yield and fodder yield, respectively (Table 3). Balanced nutrient application might promote enzyme activities which triggered sorghum growth and development, consequently improving the yield of sorghum [44]. Higher dry matter and fodder yield in T 6 (80-40 kg ha −1 ) is a result of better soil nutrients suitable for nutrient uptake and accessibility, which resulted in accelerated cell division, enlargement and elongation.…”