Der Anbau von Linsen und Erbsen im Gemenge

In Germany, lentils (Lens culinaris) are traditionally grown in mixture with cereals to reduce lodging and weed pressure. To test semi-leafless pea (Pisum sativum) as an alternative companion crop instead of dwarf oat (Avena sativa), a field trial was conducted in 2015 at the organic research station of the University of Hohenheim, south-west Germany. The three crops were cultivated in pure stands and in ratios of 1:3, 1:1 and 3:1 (lentil : pea or oat). Focus was on comparing lodging resistance, weed suppression, and grain yield. Lodging was low in all mixtures but high in lentil pure stands. Yields were very high for lentils and peas but rather low for oats (3.2 t ha-1, 4.9 t ha-1, and 3.2 t ha-1, in pure stands). Similarly, high lentil yields were achieved in the mixtures lentil-pea 3:1 (3.0 t ha-1), lentil-oat 3:1 (2.9 t ha-1), and lentil-oat 1:1 (2.7 t ha-1). Compared with pure stands, land use efficiency was up to 20 % higher in lentil-pea mixtures and up to 33 % higher in lentil-oat mixtures. When compared with lentil pure stands, weed biomass was up to 26 % (lentil-pea 1:3) lower in mixtures with pea and up to 61 % (lentil-oat 1:1) lower in mixtures with oat. Overall, semi-leafless pea is a good alternative to dwarf oat as a companion crop for lentils

Entwicklung samenfester Brokkoli-Genotypen (Brassica oleracea convar. Botrytis var. Italica): Vergleich physikalischer und sensorischer Merkmalsausprägungen

This study compared physical and sensory quality traits of three breeding lines and one hybrid of organic broccoli to find suitable open pollinating variety with high potential for marketability. An Instron texture analyzer was used to measure the firmness of the texture. Descriptive and hedonic tests were done to assess sensory quality. The evaluation of the genotypes by the panelists showed a trend to rank the lines as “good” in respect to their sensory properties and their outer appearance. CHE-MIC-31 was the firmest open pollinating genotype. Results of this study showed that this breeding line has the potential for marketability because of it’s superior physical and sensory attributes

Does conversion to reduced tillage really increase soil organic carbon stocks in organic arable farming?

Aggravation of weather extremes increases awareness of climate change consequences. Mitigation options are in demand that aim to reduce the atmospheric concentration of greenhouse gases. Amongst others, the conversion from ploughing to reduced tillage is argued to increase soil organic carbon (SOC) stocks as an accumulation of SOC in topsoil layers is commonly reported. Yet, reviews and meta-analyses describe various results from significant increases to just a redistribution of SOC in the soil profile. Reasons can be found in different sampling depths, SOC and bulk density measurement procedure, and stock calculation (equivalent soil mass vs. equal sampling depth). Furthermore, few studies evaluated the impact of organic farming systems. In nine long-term experiments on tillage systems in temperate Europe (France, Germany, Netherlands, and Switzerland), a common soil sampling campaign took place in spring and autumn 2017, and spring 2018. All trials represent common mixed organic farming systems of the respective region and contain plots with conventional and reduced tillage practices. While climatic conditions are similar, soil types vary from sandy to clayey soils. We took three undisturbed soil cores with driving hammer probes (8 cm in diameter) in each plot (minimum 3 plots per treatment) to a maximum depth of 100 cm and divided the cores in the increments 0-30, 30-50, 50-70, and 70-100 cm. The topsoil (0-30 cm) was further divided into the different tillage depths of the respective trial. We determined bulk density and organic carbon concentration as main variables and soil texture and pH as co-variates for each sample and collected C-inputs for each plot in all trails on a yearly basis. Multivariate statistics will enable the comprehensive evaluation of tillage effects on SOC stocks up to a depth of 100 cm in organic long-term trials. Texture, trial age, and the co-variate C-input will be decisive for the development of SOC stocks and enable the evaluation of carbon sequestration potentials of agricultural soils through improved tillage practices

DOMINO – Synthesis of Soil Management Strategies Integrating Plant and Waste Based Alternative Fertilizers

The project DOMINO (http://www.domino-coreorganic.eu/) focused on the evaluation of alternative fertilisers based on locally available wastes, legume-based materials and vermicompost extracts as alternatives to animal-based fertilizers from conventional agriculture in apple orchards. The project included incubation experiments, pot and field experiments in different European countries. In addition, a survey on nutrient budgets and soil nutrient status in organic fruit orchards was conducted in Germany. The evaluation of the fertilizers encompassed also their impact on soil nematodes and microbial activity and biodiversity. Considering all pros and cons, there is no single ideal solution for fertilization. An integrated approach using fertilizers based on legumes in combination with stillages that provide N early in the season can enhance farm internal N cycles leading to an overall higher N efficiency

Responses of soil organic carbon, aggregate diameters, and hydraulic properties to long-term organic and conventional farming on a Vertisol in India

Organic matter management can improve soil structural properties. This is crucial for agricultural soils in tropical regions threatened by high rainfall intensities. Compared to conventional farming, organic farming is usually deemed to increase organic carbon and improve soil structural properties such as stability and permeability. However, how much, if any, buildup of organic carbon is possible or indeed occurring also depends on soil type and environmental factors. We compared the impact of seven years of organic farming (annually 13.6 t ha−1 of composted manure) with that of conventional practices (2 t ha−1 of farmyard manure with 150–170 kg N ha−1 of mineral fertilizers) on soil structural properties. The study was conducted on a Vertisol in India with a two-year crop rotation of cotton soybean wheat. Despite large differences in organic amendment application, organic carbon was not significantly different at 9.6 mg C g−1 on average in the topsoil. However, the size distribution of water-stable aggregates shifted toward more aggregates <137 μm in the organic systems. Cumulative water intake was lower compared to the conventional systems, leading to higher runoff and erosion. These changes might be related to the lower pH and higher exchangeable sodium in the organic systems. Our results indicate that higher application of organic amendments did not lead to higher soil organic carbon and associated improvement in soil structures properties compared to integrated fertilization in this study. Chemical properties may dominate soil aggregation retarding the uptake and integration of organic amendments for sustainable agricultural intensification in tropical, semiarid climates

Stan i perspektywy rozwoju rolnictwa ekologicznego w Polsce i w Niemczech

Celem artykułu było przedstawienie i ocena stanu oraz perspektyw rozwoju rolnictwa ekologicznego w Polsce w porównaniu z sytuacją w Niemczech. Korzystano z danych wtórnych pochodzących z ogólnopolskich raportów polskich i niemieckich, które dotyczyły lat 2011-2014 oraz dostępnych fragmentarycznych danych z lat późniejszych

Changes in surface reactivity and organic matter composition of clay subfractions with duration of fertilizer deprivation

11 pages, 4 figures, 5 tables, 29 references.Preservation of organic matter in soils depends on the chemical structure of organic compounds and on the surface properties of the mineral matrix. We tested the effect of mineral surface reactivity on organic matter decomposition by (i) investigating changes of organic matter composition in clay subfractions of an illitic Haplic Chernozem along a time series of fertilizer deprivation and (ii) simultaneously characterizing the reactivity of mineral surfaces. The soil was subjected to fertilizer deprivation for 18, 44 and 98 years, respectively. Mineral surface properties were characterized by selective dissolution of pedogenic oxides. The number of hydroxyls released after exposure to sodium fluoride was taken as an index for mineral surface reactivity. Organic soil constituents were determined by 13C cross-polarization magic-angle spinning nuclear magnetic resonance (13C CPMAS NMR). Clay subfractions had different mineral surface properties. The coarse fractions have more reactive surfaces and contain more organic carbon than the fine clay fractions. Mineral surface properties are constant over time and are not affected by fertilizer deprivation. Surface reactivity is a function of iron oxide density and controls carbon concentrations in the clay subfractions. Within the time frame of our investigation, alkyl C and aromatic C responded to the duration of fertilizer deprivation, but were indifferent to mineral surface reactivity. O–alkyl C seems to be protected by interactions with pedogenic oxides.This work was financially supported by the Deutsche Forschungsgemeinschaft (SPP 1090, Kl 1139/3-1).Peer reviewe