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Long-term field experiments are important for assessing the yield response of crops to different tillage systems and pre-crops. An experiment was established in 1996 in Raasdorf (Austria) on a chernozem with four tillage treatments (mouldboard ploughing (MP), no-till (NT), deep conservation tillage and shallow conservation tillage) and two crop rotations. Winter wheat yields were generally at similar levels with all four tillage systems in most years between 1998 and 2012. Yields increased with higher amounts of rainfall during the vegetation period (from October until June) with the smallest increase among tillage treatments in NT. This indicates that MP can be superior to NT regarding yield at higher amounts of rainfall. Pre-crops considerably influenced winter wheat with higher yields after maize, soybean and winter wheat than after sugar beet. In one year with high rainfall, a tillage × pre-crop interaction showed that yields were lower after maize in NT than in other tillage systems whereas yields after sugar beet tended to be higher with NT in years with low rainfall.

Long-term field experiments are important for explaining tillage and rotation effects on soil fertility and to de - velop sustainable nutrient management strategies. An experiment was established in 1996 in Raasdorf (Aus- tria) on chernozem with four tillage treatments (mouldboard ploughing (MP); no-till; deep conservation tillage and shallow conservation tillage) and two crop rotations. Soil samples were taken in November 2003 from 10 cm soil layers down to 40 cm to assess the effects on pH, carbonate content (CaCO 3 ), soil organic carbon (SOC), total nitrogen (N t ), potentially mineralizable N (PMN) and plant-available phosphorus (P) and potassium (K). Soil pH and CaCO 3 were not affected by soil tillage. SOC, N t , PMN, P and K increased in the uppermost soil layer with reduced tillage intensity. SOC, N t , P and K were more evenly distributed in MP whereas a generally higher decline downwards the soil profile was observed with lower tillage intensity. Lower tillage intensity resulted in a decrease of P and K in 30-40 cm. Rotation affected pH and K distribution in the soil whereas the other parameters were not affected.

Amaranth is a promising C4-crop. However, for a wider spread of the crop a better understanding of factors that are influencing yield formation is crucial for optimizing the plant phenotype and enhancing yield. The present study wanted to clarify the effects of assimilate sources and sinks on yield formation by artificially altering source or sink size. Field experiments were conducted in Eastern Austria during three years with three genotypes, applying source-sink manipulation treatments at mid flowering (control, 50% of inflorescence removed, 50% or 100% of leaves removed). At maturity we measured shoot, inflorescence and grain dry matter, thousand kernel mass and number of seeds per plant. An average grain yield level of about 3.5 t/ha dry matter on control plots indicated favorable growth conditions for amaranth in general. The removal of all leaves had a strong detrimental effect on all parameters, but severity of yield reduction due to defoliation differed between genotypes, ranging from –49% to –73%. Contrastingly, 50% flower reduction did not have any significant effects. Also with 50% defoliation no significant yield reduction was observed. We conclude that source strength of amaranth during flowering is more yield limiting than its sink capacity.

Arbuscular mycorrhiza fungi (AMF) colonize roots of host plants and promote plant growth due to improved uptake of nutrients. While the effects on P uptake are well known, the relevance of AMF for the uptake of other nutrients is less investigated. In the present paper we studied contents of N, P, K, Ca, Mg, Fe, Mn, Cu, and Zn in the legume chickpea in pot experiments during two seasons. Beside the control, the following treatment combinations: (i) the inoculation with the commercial AMF product 'Symbivit ® '; (ii) soil sterilization before inoculation, and (iii) mineral nitrogen application. A moderate level of AMF colonization (18-55% of roots), enhanced the nutrient up- take of chickpea. With P, Mn, and in 2006 also with K, Cu, and Fe the nutrient concentrations were also elevated, even along with a simultaneous increase in plant biomass. Soil sterilization or fertilization with N showed no sig- nificant effect on nutrient uptake and biomass production.

The introduction of a new crop requires adapted genotypes as well as optimum crop management practices. This study was conducted to determine the optimum crop density of adapted grain amaranth genotypes in the Pannonian region of Eastern Austria. The genotypes Neuer Typ (A. hypochondriacus), Mittlerer Typ (A. hypochondriacus) and Amar (A. cruentus) were established at plant densities of 8, 17 and 35 plants/m 2 in 2002 and 2003. Average hand-harvested yields ranged from 2200 to 3000 kg/ha without significant genotypic differences. Genotypes differed in thousand seed weight (0.55–1.04 g), time from sowing to harvest (97–130 days), grain water content at harvest (24–38%), microbial infestation of air-dried grain (0.2–118.6 cfu × 10 6 /g), germination (29–79%) and grain composition. Grain contents fell within the following ranges: crude protein 15.2–18.6%, crude fat 5.4–8.6%, crude fibre 3.5–4.2%, ash 2.7–3.2%, and carbohydrates 66.7–72.7%. High grain water contents involved stronger microbial infestation and reduced germination. Crop density affected neither grain yield nor grain quality.