Dr Dorota Pikuła¹

¹Institute Of Soil Science And Plant Cultivation State Research Institute, Puławy , Poland

Introduction: Tracing of changes in soil quality as influenced  by different farming practices, such as crop rotations or fertilization requires long-term field studies (Reeves 1997, West and Post 2002).  Such studies are particularly relevant to soil organic matter (SOM), the most important indicator of soil quality, which is also the most often reported attribute due to its impact on other physical, chemical and biological characteristics of soils. Results of long-term field experiments clearly indicate that organic amendments, particularly with animal manures, diversified crop rotation systems with proper application of mineral fertilizers leading to higher crop yields and thus to higher amounts of postharvest residues are beneficial for sustaining or accumulation of soil organic matter (SOM) in agricultural soils.  In this study, based on a long-term field experiment, we report that even large input of organic matter, including farm yard manure and mustard  may  have a beneficial or negative  effects for light soil.

Objectives: The aim of this study was to compare selected biological and chemical characteristics of un-limed soil on which for over 30 years crops were grown in two crop rotations similar with respect to N fertilization and manure application but differing with respect to total organic matter input (mustard green manure, one year clover-grass ley).

Material and method: The study was conducted on the basis of a three-factor long-term field experiment carried on since 1980 at the Experimental Station Grabów of the Institute of Soil Science and Plant Cultivation in Puławy (Poland), on a soil classified Albic Luvisol  with loamy sand texture. The experiment includes two 4-years crop rotations (I factor) with the following crops: rotation A – recognized as reducing SOM (maize for grain, winter wheat, spring barley and corn for silage] and rotation B – considered to enriching SOM (maize for grain, winter wheat (after w. wheat harvest  mustard is grown as green manure), spring barley with undersown clover-grass mixture, clover-grass ley).  Within each rotation field application rates of farm yard manure (II factor) and inorganic N fertilizer (III factor) were varied in a split-plot design replicated in four blocks per field. Manure rates assigned to main plots are as follows: 0, 20, 40, 60 and 80 t/ha. Manure is applied in the autumn preceding potatoes (presently maize) once per 4-year cycle.  Four N fertilizer rates (N0, N1, N2 and N3) were assigned in 1988 to plots within each main plots, that is per manure rate. In this experiment wheat straw and barley straw is harvested and no lime is applied to demonstrate buffering properties of farm yard manure (FYM).

Results: The soil in RotB with an increased input of OM (GM and 1-year GCL),  which accumulated significantly larger amounts of soil organic carbon and soil microbial biomass C, had higher activities of dehydrogenase and acid phosphatase enzymes and gave significantly higher winter wheat grain yields compared to the soil in RotA. However, in the absence of liming, the soil in RotB, contrary to that in RotA, became more acidic, reduced the  activity of alkaline phosphatase, showed lower contents of Ca and Mg, and contained a diminished proportion of the >0.5 mm macroaggregates fraction. These soil deteriorative effects of crop rotations delivering larger amounts of OM have not been reported so far. In both rotations FYM applied once per 4-year rotation at 40 Mgha−1 improved all the tested soil properties and had mitigating effects on the negative changes found in the soil of RotB. Fractions of humic acids, fulvic acids and humins, and biomass characteristics of soil microorganisms were higher in B-crop rotation than in A-crop rotation, which indicates a better and more stable quality of organic matter, including shifting.

Biography:

–  Research on the dynamics of carbon in the soil

– Studies on the determination of soil organic matter  and determination of fractional composition of humus

Achievements in the field of industrial property rights: patents, patent applications

Professional memberships

MOEL – Mittel und Osteuropaischer Lander (2006)

“PROFICIENCY” (2009-2014). Scientific training – Soil Quality. Slovakia, Nitra, Agricultural University in Nitra, project Proficiency: Different methods of fractionation of soil humus, creating databases Corg. in soil, carbon management index in the soil (1-29 November, 2010).

– Executor of subtask of the research project “Compatibility of Agricultural Management Practices and Types of Farming in the EU to enhance Climate Change Mitigation and Soil Health (CATCH-C)” (2012-2014). Netherlands, Wageningen UR, Plant Research International  B.V. Business Unit Agrosystems Research, October 2013: ,,Developing of  biometric results of long – term field experiment”.

– Manager and executor of the statutory topic ,,Specyfying of the values of reproduction and degradation coefficients of soils organic matter (SOM), (statutory grant of Ministry of Science and Higher Education) (2008-2011).

– Manager and executor of the statutory topic ,,Assessment of the quantity and quality of soil organic matter, depending on fertilization and selection of plants in crop rotation “, (statutory grant of Ministry of Science and Higher Education (2012-2015).