Despite the successes of the Green Revolution, about a billion people are still undernourished and food security in the developing world faces new challenges in terms of population growth, reduced water resources, climate change and decreased public sector investment. It is also becoming widely recognized that poverty is a cause of environmental degradation, conflict and civil unrest. Internationally coordinated agricultural research can play a significant role in improving food security by deploying promising new technologies as well as adapting those with well-established impact.

In addition to the genetic challenges of crop improvement, agriculturalists must also embrace the problems associated with a highly heterogeneous and unpredictable environment. Not only are new genetic tools becoming more accessible, but a new generation of quantitative tools are available to enable better definition of agro-ecosystems, of cultivar by environment interactions, and of socio-economic issues, while satellite imagery can help predict crop yields on large scales. Identifying areas of low genetic diversity – for example as found in large tracts of South Asia – is an important aspect of reducing vulnerability to disease epidemics. Global strategies for incorporating durable disease resistance genes into a wider genetic background, as well as participatory approaches that deliver a fuller range of options to farmers, are being implemented to increase cultivar diversity.

The unpredictable effects of environment on productivity can be buffered somewhat by crop management practices that maintain healthy soils, while reversing the consequences of rapid agricultural intensification on soil degradation. Conservation agriculture is an alternative strategy that is especially pertinent for resource-poor farmers.

The potential synergy between genetic improvement and innovative crop management practices has been referred to as the Doubly Green Revolution. The unique benefits and efficiency of the international collaborative platform are indisputable when considering the duplications that otherwise would have been required to achieve the same impacts through unilateral or even bilateral programmes. Furthermore, while the West takes for granted public support for crucial economic and social issues, this is not the case in a number of less-developed countries where the activities of International Agricultural Research Centres (IARCs) and other development assistance organizations can provide continuity in agricultural research and infrastructure.

Smallholder cropping systems are a vital component in the agricultural sectors of tropical Asia, especially in the developing nations. These systems are important for producing food and providing a livelihood to a major proportion of the populations of Asia. While the rice systems, usually cultivated under puddled conditions are considered stable, the upland or highland units, which provide a range of food, fibre and feed commodities, are generally situated on marginal lands. Low soil fertility, erosion, sub-optimal crop management and subsistence farming conditions characterize these units. Hence, these units require improved but low cost strategies to reverse the trend of lower productivity, loss of sustainability and most importantly, the loss of livelihood for the farming populations. Among the many strategies available, the regeneration of soil fertility through agronomic measures would be a useful and easily adoptable method of enhancing productivity of tropical Asian upland smallholding farming units. The methods available include the revival of age-old traditions such as adding organic matter directly to soils, green manuring and mimicking forest ecosystems through agroforestry. Agronomic measures using plants to enrich the soil and regenerate its supporting capacity are presented in the present paper. Relevant examples are cited to highlight the potential of these methods for regenerating productivity of the upland smallholder farming units and more importantly the agro-based livelihood of a large majority of the populations of tropical Asia.

The impact of organic, compared with conventional, farming practices on N leaching loss was studied for Danish mixed dairy and arable farms using an N balance approach based on representative data. On mixed dairy farms, a simple N balance method was used to estimate N surplus and N leaching loss. On arable farms, the simple N balance method was unreliable due to changes in the soil N pool. Consequently, the Farm ASSEssment Tool (FASSET) simulation model was used to estimate N surplus, N leaching loss and the changes in the soil N pool.

The study found a lower N leaching loss from organic than conventional mixed dairy farms, primarily due to lower N inputs. On organic arable farms, the soil N pool increased over time but the N leaching loss was comparable with conventional arable farms. The soil N pool was increased primarily by organic farming practices and incorporation of straw. The highest increase in the soil N pool was seen on soils with a low initial level of organic matter. The N leaching loss was dependent on soil type, the use of catch crops and the level of soil organic matter, whereas incorporation of straw had a minor effect. N leaching was highest on sandy soils with a high level of soil organic matter and no catch crops. The present results stress the importance of using representative data from organic and conventional farming practices in comparative studies of N leaching loss. Lack of representative data has been a major weakness of previous comparisons on N leaching losses on organic and conventional farms.

The current study, performed in Castilla-La Mancha (Spain) in 2003–04, reports the growth, nutrition, tolerance to transplanting stress, and resistance to Verticillium dahliae of olive plantlets (Olea europaea L.) inoculated with different arbuscular mycorrhizal (AM) fungi (Glomus mosseae, G. intraradices and G. claroideum). Inoculated plants tolerated the stress of transplanting better than non-inoculated plants. Compared with controls, plantlets inoculated with any of these three Glomus species grew taller, had more and longer shoots, and showed higher plant N, P and K concentrations. However, colonization seemed to have no influence on resistance to V. dahliae.

The alkane patterns of the dominant forage species of the typical steppe grassland in Inner Mongolia were clarified, and the effects of species, sampling time and site on the concentrations of alkanes were evaluated. The results showed that alkanes with odd-numbered carbon chains in the range C25 (n-pentacosane)–C35 (n-pentatriacontane) were predominant in cuticular wax in five dominant grasses of the typical steppe. The C31 (n-hentriacontane) alkanes were always present in the highest concentration in the grass species, especially in the Stipa daicalensis and Stipa grandis. Samples of Artemisia frigida contained not only high concentrations of odd-chain alkanes, but also the even-chain ones compared with other species. The effects of species and sampling time on alkane concentrations were significant, accounting for 0·912 and 0·067 of the total variance, respectively. The site effects on odd-chain alkanes were less than on even-chain. The results of principal component analysis indicated that the patterns of alkane concentrations in the five dominant species could be clearly distinguished during the whole growing season. Therefore, it should be possible to achieve accurate and precise estimations of intake and diet composition of grazing animals of the typical steppe grassland in Inner Mongolia using the alkane technique.

Alternate 2·4 m wide strips of a mixture of birdsfoot trefoil (Lotus corniculatus L.) with white clover (Trifolium repens L.) (BW), and of red clover (Trifolium pratense L.) (RC) were offered in the proportions (by area) of 0·80[ratio ]0·20, 0·67[ratio ]0·33, 0·33[ratio ]0·67 and 0·20[ratio ]0·80 to yearling heifers in groups of three for periods of 3 days over four replicates in time, balanced for effects of previous treatments. Observations on the distribution of grazing activity and biting rate were made over 3 h periods each evening, and on the morning of Day 2. Biting rates were consistently higher on BW than RC (52·3 v. 46·3±0·59 bites/min, P<0·001). Initially the animals showed a strong tendency to concentrate grazing on the sward of smaller proportional area, but the selection coefficient (log θ) changed from positive to negative with time as herbage on minority strips was depleted. These results are discussed in the context of concepts of partial grazing preference.

The effects of manipulation of sward maturity on ingestive behaviour and diet selection of grazing cattle were tested in two experiments using legumes which are equally preferred by cattle. Yearling heifers, in groups of three, grazed plots formed by alternate 2·4 m wide strips of a mixture of birdsfoot trefoil (Lotus corniculatus L.) and white clover (Trifolium repens L.) (BW) and strips of red clover (Trifolium pratense L.) (RC). The treatments comprised four combinations of each of the two swards at two contrasting levels of maturity/height replicated over four successive 3-day periods, in an order which balanced the effect of previous treatments. Observations of the distribution of grazing activity and biting rate were made over 3-hour periods each evening and in the morning of Day 2.

Rate of biting was generally greater on immature than mature swards, and on BW than on RC, with little evidence of interactions between these effects. The animals demonstrated partial preference throughout the two studies, the proportion of grazing time devoted to BW being 0·40±0·010 in Expt 1 and 0·47±0·017 in Expt 2. The distribution of grazing time between sward type and maturity combinations was influenced progressively by herbage mass and height contrasts as strips were grazed down. An overall analysis using the results from these studies and a companion experiment indicated differences between studies in partial preference for BW and RC which appeared to be related to variations in sward morphology.

Cattle tuberculosis in Great Britain is out of control, rising at some 18% a year, but there is great confusion as to why cattle control measures are not working (Hancox 2004a). Culling over 10000 badgers so far in the Krebs Randomised Badger Culling Trial has had no effect, despite repeated calls for mass culls by farmers and vets (Hancox 2004b). Badgers are blamed for this crisis because it is claimed cattle-to-cattle transmission is unimportant, and badgers with TB are found after repeat breakdowns in herds supposedly free of TB after negative tests.