Field trials in Europe with Miscanthus over the past 25 years have demonstrated that interspecies hybrids such as M. 9 giganteus (M 9 g) combine both high yield potentials and low inputs in a wide range of soils and climates. Miscanthus hybrids are expected to play a major role in the provision of perennial lignocellulosic biomass across much of Europe as part of a lower carbon economy. However, even with favourable policies in some European countries, uptake has been slow. M 9 g, as a sterile clone, can only be propagated vegetatively, which leads to high establishment costs and low multiplication rates. Consequently, a decade ago, a strategic decision to develop rapidly multiplied seeded hybrids was taken. To make progress on this goal, we have (1) harnessed Correspondence: John Clifton-

In many parts of Europe there has been a net decline in the use of forage legumes since the 1980s, despite the reputed value of legumes for low-input livestock production systems. The political environment within which livestock farming in much of Europe operates (Common Agricultural Policy) is shifting the balance of economic advantage towards legumes and away from high usage of inorganic fertilizer. This has already been found for legume and grass-legume silages when compared with grass silages with a potential economic gain for farmers averaging 137 ha )1 , corresponding to an annual benefit for the European livestock farming sector of as much as 1300 million. Recent literature has shown that legume-based grazing systems have the ability to reduce environmental problems by increasing the efficiency of N use and by avoiding a high transient surplus of soil mineral N. From the perspective of livestock nutrition, when forage legumes contain moderate levels of secondary compounds, such as condensed tannins and flavonoids, they offer considerable advantages including increased efficiency of N utilization within the digestive tract, reduced incidence of bloat hazard and higher resilience to parasites.Nevertheless, these benefits are partially counterbalanced in both temperate and Mediterranean regions by difficulties in establishment, maintenance and management under grazing. To gain knowledge on mixed grass-legume pastures, further research is required on: (i) the development of sustainable systems of livestock production which can maintain sward persistence and agricultural production under environmental stress; (ii) increasing knowledge of soil-plant-animal relations for a wide range of leguminous species, and under different soil types and climatic situations; and (iii) the benefits for consumers of food produced from low-input livestock production systems.

Alley cropping agroforestry systems (ACS) are ascribed to have manifold positive ecological effects; nevertheless their application is still limited due to uncertain productivity of the agricultural crop, especially in the tree-crop competition zone. Therefore, this study investigated the variability of oilseed rape and winter wheat yield, respectively, at different distances from the tree strip edge in 2016 and 2017 in an ACS established in 2008 in northern Germany. The ACS consisted of strips of fast-growing poplars alternating with narrow (48 m) and wide (96 m) crop alleys, each with a crop rotation including winter oilseed rape and winter wheat. Each tree strip contained 6 rows of poplars with a density of 10,000 trees per ha. Moreover, multi-year (2009-2016) crop yield data of oilseed rape and winter wheat in the narrow and wide crop alleys were compared with those of a corresponding non-agroforestry control field. In general, crop yields observed in 2016 and 2017 in the narrow crop alleys at 1 m from the tree strip edges were on average 77% (oilseed rape) and 55% (winter wheat) lower than in the middle of the crop alley. One reason for low yield close to the tree strips might be the leaf litter coverage of the seedlings in autumn. Leaf litter deposition was highest at 1 m on the windward and the leeward side of the tree strips in 2015 and on the leeward side in 2016, respectively. However, the average long-term crop yields of the narrow crop alley, the wide crop alley and the control field did not differ substantially among each other. Although oilseed rape and winter wheat yields were lower close to the tree strips, this yield reduction did not negatively influence the average long-term crop yields of the ACS. Keywords Alley cropping Á Crop yields Á Winter wheat Á Oilseed rape Á Yield variability Á Competition zone Á Long-term yield Á Leaf litter

Before hydrochars can be applied as soil amendments in agriculture, information about how hydrochar application affects soil nutrient cycles and plant growth are necessary. In this study, incubation experiments were performed to investigate hydrochar effects on N concentrations (NO$ _3^- $, NH$ _4^+ $) in soils with different N pools (soil N, fertilizer N). A set of pot trials with three crop species (barley, phaseolus bean, leek) was conducted to determine hydrochar effects on plant N availability and biomass production after mineral‐N fertilization. Results of the incubation experiments show that hydrochar reduced the concentration of mineral N in soil within the first week after incorporation, especially that of nitrate. This was particularly evident, when hydrochars with high C : N ratio, high DOC and low mineral‐N contents were applied. Hydrochars promoted biomass production of barley and phaseolus bean in pot trials, which can be partly attributed to an increase in soil pH after hydrochar incorporation. Dry‐matter yield of leek tended to decrease after hydrochar application. Hydrochars with high C : N ratio decreased the plant's N content, an effect that was strongest with increased hydrochar concentration. Hydrochars with low C : N ratio did not affect the crop's N uptake. Our results show that the use of hydrochars as amendment in arable field or horticultural pot production will require an adjustment of N‐mineral‐fertilization strategies.

The productivity of eight forage maize cultivars (Zea mays L.) in response to N was investigated in a 3-year field experiment located in Northern Germany. Nitrogen fertilizer applications were zero, 50 and 150 kg N/ha given each year shortly after sowing. Each cultivar was grown on the same plot, beginning in 1993, following the ploughing up of a 2-year old grass sward, to which slurry had been added. Plants were sampled regularly for dry matter (DM) production and N uptake. A non-linear regression equation was used to compare the data. Growth analysis and N uptake characteristics (maximum crop growth rate, duration of maximum crop growth rate, period until maximum crop growth rate, maximum N uptake rate, duration of maximum N uptake rate, period until maximum N uptake rate) which derived from the function were used to compare the cultivars.The cultivars DM yield and N uptake were highest in 1993 and declined in the next two years partly due to a decrease in soil N mineralization following the ploughing of the grass sward and partly due to the drier weather conditions during the summers of 1994 and 1995. Duration of the maximum crop growth rate was greater during the cool year of 1993. In contrast, maximum crop growth rate was at its highest in the dry vegetation period of 1995. A significant N×cultivar interaction for growth analysis characteristics (P<0·05) was found in 1995. Cultivars with a high maximum crop growth rate (above the average value of the eight cultivars tested) and a short duration of maximum crop growth rate (below the average) accumulated more DM than those genotypes which showed an inverse relationship.Increasing N yield was determined by increased maximum N uptake rather than by a greater duration of maximum N uptake. A significant N×genotype interaction for N uptake parameters (P<0·05) was found in 1994 and 1995. With some exceptions, cultivars with a high maximum N uptake rate (above average) accumulated more N per unit area compared to those genotypes which had low uptake rates. The exceptions had a longer duration of uptake, which could not, however, compensate for the lower rate. Maximum N uptake rate occurred earlier and duration of maximum N uptake rate increased compared to the start and duration of maximum crop growth rate. Especially in 1995, the amount of N taken up before the day of maximum crop growth rate accounted for 71% of total N uptake. The N uptake rate and the amount of accumulated N until the day of maximum crop growth rate were highly correlated with DM yield.This result indicates the availability of genotypic variability in crop growth and N uptake rate to assist the improvement of DM yield by selection.