Endla Reintam

Efficiency of Estonian grain farms in 2000-2004

The aim of this study is to analyse the efficiency of Estonian grain farms after Estonia’s transition to a market economy and during the accession period to the European Union (EU). The non-parametric method Data Envelopment Analysis (DEA) was used to estimate the total technical, pure technical and scale efficiency of Estonian grain farms in 2000–2004. Mean total technical efficiency varied from 0.70 to 0.78. Of the grain farms 62% are operating under increasing returns to scale. Solely based on the DEA model it is not possible to determine optimum farm scale and the range of Estonian farm sizes operating efficiently is extensive. The most pure technically efficient farms were the smallest and the largest but the productivity of small farms is low compared to larger farms because of their small scale. Therefore, they are the least competitive. Since pre-accession period to the EU, large input slacks of capital have replaced the former excessive use of labour and land. This raises the question about the effects on efficiency of the EU’s investment support schemes in new member states.

Effect of Cirsium arvense L. on soil physical properties and crop growth

The re-cultivation of abandoned areas creates weed control problems. The main problems in these areas are perennial weeds, such as Cirsium arvense L. but this perennial deep-rooted plant may have a beneficial effect on the physical properties of compacted soil. In order to study the effect of C. arvense’s root system on soil properties, the field experiment and a survey of arable fields were conducted in Estonia. The soil bulk density and penetration resistance were measured from soils covered by C. arvense or spring barley (Hordeum vulgare L.) on compacted and un-compacted soil. The results showed significantly lower penetration resistance and bulk density underneath C. arvense than under barley in both the field experiment and a field survey on arable soils. The shoot mass of C. arvense was less affected than the shoot mass of barley by soil compaction and was caused by C. arvense’s better ability to develop its root system in compacted soil. Wheat yield, on soils affected by C. arvense, was increased by 28% on loose soil and 37% on compacted soil. It may be concluded that in areas affected by deep-rooted weed species, such C. arvense, the soil’s physical properties will improve at least in the first two years.

Soil Nutrient Evolution during the First Rotation in Organic and Conventional Farming Systems

Since 2008, a 5-year crop rotation experiment (winter wheat, pea, potato, barley undersown with red clover, and red clover) has been run in Tartu, Estonia, to evaluate the changes in soil chemical parameters under four fertilizer managements: (1) unfertilized conventional plots (conventional I), (2) conventional plots with addition of mineral fertilizers (conventional II), (3) organic plots with cover crops during the winter period (organic I), and (4) organic plots with the same cover crops plus a yearly amendment of 40 t ha–1 of cattle manure (organic II). After the first rotation, results showed significant differences (P < 0.05) in soil acidity dependent on the system with mean values ranging between 5.67 (conventional II) and 6.10 (organic II). In the organic II system, manure had a significant effect on the system, increasing the organic carbon (C) content by 0.34%, but in both organic systems, both cover crops and cattle manure were insufficient for maintaining a constant level of plant-available phosphorus (P) or potassium (K) in the soil. In the conventional II system, mineral fertilizers provided a sufficient amount of nitrogen (N) to the system and increased the concentration of P to 8.7 mg per kg. The yearly mineral or organic amendments did not counteract the significant decrease in soil-available K after the first rotation. Lastly, calcium (Ca) and magnesium (Mg) availability, strongly influenced by the soil pH local conditions, decreased with time for all systems even though organic ones presented greater concentrations of both compounds. In conclusion, the four fertilization systems managed independently would not guarantee a constant soil nutrient concentration after the first rotation.

Effect of annual lupines growing on compacted sandy loam Stagnic Luvisol

Abstract The aim of the investigation presented in this paper was to identify the suitable and less energy-demanding methods to loose the subsoil compaction instead of mechanical subsoil loosening. The experiments with lupines (Lupinus luteus L. and Lupinus angustifolius L.) and spring barley (Hordeum vulgare L.) were made on the sandy loam Stagnic Luvisol. The field was compacted by tractors MTZ-82 (total weight 4.84 megagram Mg) characterized by multiple tyre-to-tyre passing. Parameters such as plants biomass (shoots and roots) and the changes in soil physical properties, the bulk density and penetration resistance, were measured. The best results showed yellow lupine on six times compacted soil where the penetration resistance was 1 MPa lower than on sites planted with barley or narrow-leafed lupine and decreased also soil bulk density on 3- and 6-times compacted soil by 0.1 and 0.05 Mg m−3, respectively. At the same time, lupine growth increased soil penetration resistance on uncompacted fields. As the positive effect of ameliorative plants growing occurs mostly in the following year, when roots are decayed and biopores are formed, further investigations with lupines are needed.

Winter cover crop effects on soil structural stability and microbiological activity in organic farming

Abstract In a field experiment based on a five-year crop rotation (pea, potato, barley undersown with red clover, red clover and winter wheat), several soil parameters, porosity, number and biomass of earthworms, total nitrogen, organic carbon, percentage of water stable aggregates and enzymatic activity, were studied during 2013 and 2014, the first and second year, respectively, since the first rotation concluded. This rotation was managed under three organic farming systems: Organic 0 (control), Organic I (with winter cover crops lately incorporated into the soil as green manure) and Organic II (with the same cover crops plus a yearly amendment of 40 t ha−1 of cattle manure). Crop rotation had a yearly positive effect on the soil bulk density, and enhanced the percentage of air filled pores; nonetheless, despite the leguminous crops in the rotation, all the systems presented a yearly decrease in total nitrogen in 2014. Cover crops along with manure only had a significant effect on enzymatic activity; however no significant effect was found in soil organic carbon content, soil particle aggregability or number and biomass of earthworms. This was connected with the intensive tillage carried out in the systems, the weather conditions and the characteristics of the organic amendments. However according to other studies these results could be transient and further long-term investigations will be needed.

Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

Abstract For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

Weed Responses to Soil Compaction and Crop Management

Soil compaction first affects physical properties, as compaction occurs when soil particles are pressed together, reducing pore space between them and increasing the soil bulk density (Lipiec & Hatano, 2003; Raper, 2005; Reintam, 2006; Reintam et al., 2009). Soil compaction also influences chemical and biological processes, such as decreasing organic carbon (C) and N mineralization, the concentration of CO2 in the soil (Conlin & Driessche, 2000), nitrification and denitrification, and activity of earthworms and other soil organisms (Ferrero et al., 2002). At high soil moisture, the difference in soil resistance between noncompacted and compacted soil is low and may be smaller than the value that limits root growth (>2 MPa). But as the soil dries, soil compaction is more observable (Hamza & Anderson, 2005). Further soil compaction effects are decreased root size, retarded root penetration, smaller rooting depth (Unger, and Kaspar, 1994), decreased plant nutrient availability and uptake (Kuchenbuch & Ingram, 2003; Reintam, 2006), and greater plant stress (Reintam et al., 2003), which are among the major reasons for reduced plant productivity and yield (Arvidsson, 1999; Reintam et al., 2009).

Assessment of promising agricultural management practices

iSQAPER project - Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience - aims to develop an app to advise farmers on selecting the best Agriculture Management Practice (AMPs) to improve soil quality. For this purpose, a soil quality index has to be developed to account for the changes in soil quality as impacted by the implementation of the AMPs. Some promising AMPs have been suggested over the time to prevent soil degradation. These practices have been randomly adopted by farmers but which practices are most used by farmers and where they are mostly adopted remains unclear. This study is part of the iSQAPER project with the specific aims: 1) map the current distribution of previously selected 18 promising AMPs in several pedo-climatic regions and farming systems located in ten and four study site areas (SSA) along Europe and China, respectively; and 2) identify the soil threats occurring in those areas. In each SSA, farmers using promising AMPs were identified and questionnaires were used to assess farmers perception on soil threats significance in the area. 138 plots/farms using 18 promising AMPs, were identified in Europe (112) and China (26).Results show that promising AMPs used in Europe are Crop rotation (15%), Manuring & Composting (15%) and Min-till (14%), whereas in China are Manuring & Composting (18%), Residue maintenance (18%) and Integrated pest and disease management (12%). In Europe, soil erosion is the main threat in agricultural Mediterranean areas while soil-borne pests and diseases is more frequent in the SSAs from France and The Netherlands. In China, soil erosion, SOM decline, compaction and poor soil structure are among the most significant. This work provides important information for policy makers and the development of strategies to support and promote agricultural management practices with benefits for soil quality.

Innovative Soil Management Practices (SMP) Assessment in Europe and China

(1) Instituto das Ciências Agrárias e Ambientais Mediterrânicas (ICAAM), University of Évora, Núcleo da Mitra Apartado 94 7006-554 Évora, Portugal (lbarao@uevora.pt), (2) 2 Centre for Development and Environment (CDE), University of Bern, Hallerstrasse 10, 2012 Bern, Switzerland, (3) University of Pannonia (UP), Deák F. u. 16., H-8360 Keszthely, Hungary, (4) Wageningen University (WU), The Netherlands, (5) Stichting Dienst Landbouwkundig Onderzoek (DLO), The Netherlands, (6) Gaec de la Branchette (GB), France, (7) Research Centre for Natural Resources, Environment and Society (CERNAS), College of Agriculture, Polytechnic Institute of Coimbra, Coimbra, Portugal, (8) University of Miguel Hernández (UMH), Spain, (9) Agricultural University Athens (AUA), Greece, (10) University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, 1000 Ljubljana, Slovenia, (11) Institute for Soil Sciences and Agricultural Chemistry, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út. 15., H-1022 Budapest, Hungary, (12) National Research and Development Institute for Soil Science, Agrochemistry and Environmental Protection (ICPA), Romania, (13) Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland, (14) Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Estonia, (15) 15 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences (IARRP, CAAS), China, (16) Soil and Fertilizer Institute of the Sichuan Academy of Agricultural Sciences (SFI), China, (17) Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources (ISWC), China

Measuring and predicting soil moisture conditions for trafficability

ABSTRACT The main cause of loss of soil structural stability is vehicle operation on unpaved wet surfaces. Unfortunately, there is a lack of continuous soil moisture data in predicting trafficable conditions. To measure changes in soil moisture conditions in real time, Percostation (Adek) sensors were installed in sandy loam Stagnosol soil at different depths. Problems with soil trafficability can be expected at the plastic limit, and the soil is unable to support vehicle operations at the liquid limit in such soils. The maximum water-holding capacity of the soil is 32%, the field capacity is 25%, the plastic limit is 22%, and the liquid limit is 30%. With rainfall of more than 10 mm d−1, the moisture content reached the plastic limit in the upper 25 cm of soil. The average increase in the soil moisture content after more than 10 mm of rain was 1–2.5% in a time frame of 2–3 hours. After rain, the previous soil moisture level was obtained within 2 to 3 days in the vegetation period. Measurements also allowed soil water balance and evapotranspiration modelling data to predict soil moisture conditions with an accuracy of one day but failed to predict in a shorter period.