Soil Fertility Clock-Crop Rotation as a Paradigm in Nitrogen Fertilizer Productivity Control

Abstract

The Soil Fertility Clock (SFC) concept is based on the assumption that the critical content (range) of essential nutrients in the soil is adapted to the requirements of the most sensitive plant in the cropping sequence (CS). This provides a key way to effectively control the productivity of fertilizer nitrogen (N_f). The production goals of a farm are set for the maximum crop yield, which is defined by the environmental conditions of the production process. This target can be achieved, provided that the efficiency of N_f approaches 1.0. Nitrogen (in fact, nitrate) is the determining yield-forming factor, but only when it is balanced with the supply of other nutrients (nitrogen-supporting nutrients; N-SNs). The condition for achieving this level of N_f efficiency is the effectiveness of other production factors, including N-SNs, which should be set at ≤1.0. A key source of N-SNs for a plant is the soil zone occupied by the roots. N-SNs should be applied in order to restore their content in the topsoil to the level required by the most sensitive crop in a given CS. Other plants in the CS provide the timeframe for active controlling the distance of the N-SNs from their critical range.

Keywords: maximum attainable yield; nitrate-nitrogen; nitrogen; nitrogen use efficiency; nitrogen-supporting nutrients; phosphorus; potassium; soil fertility management.

Figure 3

Patterns of nutrient accumulation during the growing season by high-yielding winter oilseed rape (simulation based on [70]).

Figure 9

Effect of K soil fertility on maize yield in two years differing in water regime (modification based on [144]). Legend: * soil K fertility level: M, medium, D, high; ** Partial factor productivity of N_f (kg grain kg⁻¹ N_f).

Figure 10

Degree of nitrate and potassium utilization in the soil during the maximum stage of K accumulation by sugar beets (based on [74]).

Figure 1

Impact of nitrogen fertilization on nutritional status of winter wheat and maize (photos by W. Grzebisz).

Figure 2

Effect of fertilization variants on yield of winter rye grown in 7-course crop rotation and monoculture (based on [65]). Legend: * Yield on the NPK variant = 100%; ** yield reduction—yield gap due to crop monoculture.

Figure 4

The stunted stature of plants due to potassium deficiency is the primary signal of yield depression in crop plants. (photos by W. Grzebisz).

Figure 5

Nitrogen (N) and potassium (K) accumulation by winter wheat in critical stages of yield formation under various water conditions; means of three growing seasons (Grzebisz, not published). Legend: The different letters indicate significant differences between the treatments (p ≤ 0.05); * irrigation and ** non-irrigation conditions of wheat cultivation, respectively; K, N, potassium and nitrogen, respectively.

Figure 6

Symptoms of phosphorus deficiency in two different species grown in humid climate zone: (a) violet plants of winter oilseed rape are not able to conduct photosynthesis); and (b) violet maize plants at BBCH 33 often fail to develop a cob. (Photos by W. Grzebisz.)

Figure 7

Effect of NPK fertilization systems on nitrogen accumulation in storage roots of sugar beets (based on Szczepaniak et al. [125]). Legend: PK—NPK100—the applied amount of P and K; N control; NP25K25—P and K applied at a dose of 25% compared to NPK100.

Figure 8

Yield of wheat response to the content of available phosphorus (based on [134]). Legend: * SR, ** SL, phosphorus sufficiency range, sufficiency level of the content of available P (determined by Olsen method).

Figure 11

The crop rotation conceptual approach for the sufficient K level and range on sandy loam for sensitive and non-sensitive K plants. Legend: ¹ CL–N-Sc, CL–Sc, CR–N-Sc, ² CR–Sc: critical level and critical range for non-sensitive and sensitive plants to the content of available K (determined by the Egner–Riehm method).