Crop capacity of winter wheat depending on the system of soilcultivation and fertilization

Abstract

In present-day conditions of agro-industrial production, to get high quality agricultural output along with the reduction in power consumption in production technologies of agricultural crops becomes of great significance. One of the important elements of power-saving technologies of agricultural crop cultivation is the optimization of soil cultivation and fertilization level. The use of rational technological measures is a guaranty of agriculture stability, as it has a serious influence on water, nutritious and phyto-sanitary regime of the soil, it is an important factor of ecological stabilization and biological balance of the environment, which are closely connected with the task of rational use of the soil and the restoration of soil fertility.     

Numerous trials show that in the conditions of a stationary experiment, when all the factors which influence yield capacity, except for the studied systems of soil cultivation, are at the same level, minimal tillage leads to the same crop capacity as a traditional soil cultivation system does. Sometimes it results in a serious crop capacity increase, in particular that of grain crops.  

The aim of the research is to define crop capacity of winter wheat under various systems of soil cultivation and fertilization.

Methodology of the research. The research was carried out in a stationary field trial in the experimental field of Bila Tserkva NAU in 2009–2011. Four systems of soil cultivation and four fertilization levels were studied. A triple replication was used, the placement of replications in the area was continuous, plots of the first order (soil cultivation) are placed in one layer, successively, systematically, and plots of the second order (fertilization levels) are placed in four layers successively.  

Farm practices in the trial are typical for research institutions and leading farms of the zone. Machines, tools and mechanisms, which are available in SPC of BTsNAU, and leading production companies are equipped with, were used to cultivate winter wheat. It was methodology and organization of the technique of performing a field trial that facilitated the experiment. Plowing at depth 15–17, 20–22 and 30–32 cm was done  with ПЛН –3-35, mould boardless soil cultivation at depth  10–12, 15–17, 20–22 and 30–32 cm – subsurface tiller КПГ –250, scuffling at depth 10–12 cm – scuffler ПЛ – 5-25 and disk plow БДВ –3.0. The following fertilizers were used: 35 % – ammonium nitrate, 20.5 % – granular superphosphate, 40 % – potassium salt and half-overperspired cattle manure on straw litter with average content of 0.5% nitrogen, 0.25% phosphorus, 0.6% potassium.         

The technique of winter wheat harvesting was direct combine-harvesting; conversion of natural units into fodder ones and digestible protein was done according to the reference book of M. M. Karpus [21]; a statistical analysis of the experimental data  was made with a disperse multi-factor analysis method.    

Results and discussions.

It has been found out that different systems of the soil cultivation produce a certain effect on crop capacity of winter wheat.

A considerable decrease of crop capacity of winter wheat grain is observed under regular mould boardless cultivation. On the average, in the years of this research this indicator was: under continuous mould board cultivation – 3.40 t/ha, under regular subsurface cultivation – 2.99, under differentiated cultivation – 3.49 and under continued shallow cultivation – 3.43 t/ha.

The productivity of winter wheat (grain+straw) was in fact at the same level when plowing and mouldboard scuffling were carried out. The substitution of a plow for a subsurface tiller resulted in a serious decrease of this factor. So, average winter wheat productivity was: at a continued mouldboard cultivation –6.64 t/ha of dry matter and 5.20 t/ha of fodder units, a regular mouldboardless cultivation – 5.94 and 4.60, respectively, a differentiated cultivation – 6.86 and 5.34 and at a continued shallow cultivation – 6.77 and 5.26 t/ha.   

 It has been established that when mineral fertilizer dose is increased, their agro-technical efficiency decreases under subsurface cultivation, and it increases when share scuffler is used.

Thus, in the unfertilized plots, in fertilized plots with N₂₀Р₃₀К₃₀ , N₄₀Р₆₀К₆₀ and N₆₀Р₉₀К_90, winter wheat productivity decreased by 0.  56; 0.64; 0.79 and 0.91 t/ha of dry matter or by 0.43; 0.55; 0.65 and 0.75 t/ha of fodder units at mouldboardless cultivation, as compared with the control; whereas at a differentiated cultivation it increased  by 0.09; 0.18; 0.27 and 0.34 t/ha of dry matter  or 0.05; 0.12; 0.19 and 0.23 t/ha of fodder units.

The highest correlation between a marketable part of the yield and a non-marketable one was recorded when soil cultivation under winter wheat was done with help of a subsurface tiller, the lowest correlation was recorded when a plow was used. So, on the average within three years this indicator was at: a continued mouldboard cultivation – 1.279, a regular mouldboardless cultivation – 1.321, a differentiated cultivation – 1.292 and a continued shallow cultivation – 1.302. 

The substitution of plowing for the cultivation with a subsurface tiller decreased the output of low-valuable part of the yield. The results of the made analysis show that a fertilization system makes the major contribution to the productivity formation of the studied crops (68 %), and variants of the soil cultivation have a smaller effect on this indicator – only 17 %, whereas year conditions define a productivity level by 7 %. 

Key words: winter wheat, crop capacity, system of soil cultivation (tillage), fertilization levels