The association of carbon isotope discrimination of grain (Δ13C) with yield performance under rain-fed and well-watered conditions was analysed using a doubled-haploid (DH) winter wheat population, derived from the cross between cvars Beaver×Soissons, within field experiments at two site-seasons. The aim of this work was to quantify associations between Δ13C and yield responses to drought and to test effects of major genes (the semi-dwarf genes, Rht-B1b, Rht-D1b, an awn suppressor gene, B1 and the 1BL.1RS wheat–rye chromosome translocation) segregating in the population for associations with Δ13C and drought performance. Carbon isotope discrimination, through its negative relationship with transpiration efficiency, may be used as a surrogate for this trait. Grain Δ13C was positively associated with grain yield under both irrigated and unirrigated conditions in each site-season and, overall, explained 0·34 of the phenotypic variation in grain yield amongst DH lines under drought and 0·14 under well-watered conditions. There was a positive association between specific leaf lamina N content (SLN) at anthesis and Δ13C under drought amongst DH lines in one site-season, suggesting higher SLN may confer increased stomatal conductance via higher photosynthetic capacity, hence increased grain Δ13C. Overall the Rht-D1b (semi-dwarf) lines had slightly higher Δ13C of grain (20·0‰) than the Rht-B1a/Rht-D1a (tall) group of lines (19·8‰). There were no significant differences between the Rht-B1b (semi-dwarf) or the Rht-B1b/Rht-D1b (dwarf) lines and the tall lines. Comparing their performance under irrigated and unirrigated conditions, the Rht groups of lines (Rht-B1b semi-dwarf, Rht-D1b semidwarf and dwarf and tall groups) responded no differently to drought for Δ13C. The Rht-D1b semi-dwarf lines had higher grain yield (9·50 t/ha) than the tall lines (8·76 t/ha), while the yield of the Rht-B1b semi-dwarf and dwarf lines did not differ significantly from the tall lines. In each site-season, the presence of the 1BL.1RS chromosome increased grain Δ13C (P<0·001), with an overall increase from 19·7‰ in the 1B lines to 20·0‰ in the 1BL.1RS lines (P<0·001). However, the 1BL.1RS and 1B lines responded similarly to drought. The effect of the presence/absence of awns on grain Δ13C was not statistically significant in either site-season. Overall, the present results show that Rht-D1b confers higher Δ13C and grain yield, and the 1BL.1RS translocation confers higher Δ13C. This implies that modern UK wheat cultivars may have lower water-use efficiency during the grain filling period than their predecessors, and therefore may require more water to fulfil their yield potential.

Dry bean (Phaseolus vulgaris L.) is a traditional crop of north-western Macedonia, Greece, where two landraces (plaki Prespas and Chrisoupoli) in particular are grown. The aim of this study was to test whether the grain carbon isotope discrimination (Δ) and ash content (ASH) are related to grain yield (GY), protein content (PC) and mean grain weight (MGW) in dry bean. As a part of a honeycomb selection programme, 21 genotypes (19 lines derived via intra-landrace honeycomb selection for single plant yield at low density plus the two original populations) were grown at two densities, 1·2 and 4·8 plants/m2 under non-limiting water conditions in a glasshouse and in the field. Genotypes differed significantly for Δ, ASH and PC under the low density. In the dense stand, genotypes differed significantly only for ASH and PC. The environment (glasshouse or field conditions) affected all the traits significantly. Neither Δ nor ASH showed strong or consistent relationships with GY and thus, they cannot serve as reliable, indirect selection criteria for GY. Strong, negative relationships between Δ and PC were found especially in the dense stand, confirming analogous results in C3 cereals. Inconsistent genotypic ranking for grain physiological traits under the different densities and environments was indicative of large genotype×environment interaction. Genotypes performed consistently for GY and MGW under both densities, showing the strong stability of these traits.

A high proportion of plant nutrients present in animal feed are excreted and therefore animal manure can be an important source of nitrogen (N) for crop production if losses of plant nutrients to the environment during storage and processing are minimized. The present study examines gaseous N losses from stored pig slurry and during composting of solid manure as affected by protein and fibre content in the feed and manure management. Two slurry storage treatments (with and without cover) and three additives to solid manure composting (straw only, straw+lime and straw+superphosphate) were examined for three common types of pig feed in Vietnam (low-protein high-fibre, medium-protein medium-fibre and high-protein low-fibre).

Feed type was found to affect the N content in pig slurry or manure and thus potential N losses. The fraction of N loss caused by N emission from covered slurry storage was 0·25–0·30 of initial N content, while that from uncovered slurry was 0·60–0·70. After 90 days of storage, 1·15–1·20 times the initial ammonium-N (NH4-N) was found in the covered slurry and 0·40–0·50 in the uncovered. The fraction of N lost during composting with superphosphate was 0·25–0·35 of initial total N, while with lime or straw the total N loss was 0·45–0·55. With added superphosphate, 1·25–1·60 times the initial NH4-N in manure was found in the compost after 80 days compared with only 0·11–0·22 for lime and 0·22–0·36 for straw only. Covering stored slurry and addition of superphosphate when composting solid pig manure are thus important methods for Vietnamese farmers to minimize N losses and produce compost with a high content of plant-available N.

Long-term (over 14 years) experiments on winter wheat (Triticum aestivum L.)–rice (Oryza sativa L.) crop rotations were conducted in Southwest China to investigate phosphorus (P) fertilizer utilization efficiency, including the partial factor productivity (PFP), agronomic efficiency (AE), internal efficiency (IE), partial P balance (PPB), recovery efficiency (RE) and the mass (input–output) balance. The seven treatments were Control, N, NP, NK, NPK, NPKM and NPKSt, representing various combinations of inorganic fertilizers (N, P and K), manure (M) and the application of rice straw (St). Without P application, the soil could supply c. 14·7–22·5 kg P/ha annually and produce, on average, c. 1·8 t/ha wheat and 6·0 t/ha rice. Phosphorus fertilization increased crop yields by 65·5 and 11·4% for wheat and rice, respectively, over the 14 years. The PFP values ranged from 80·2 to 177 kg grain/kg P fertilizer for wheat and from 222 to 255 kg/kg for rice in the NPK treatments. However, the mean AE over the 14-year period was 31·9 and 21·3 kg grain/kg inorganic P fertilizer for wheat and rice, respectively. The mean IE was 214 and 318 kg grain/kg P uptake for wheat and rice, respectively, during the cultivation period. The PPB for the whole rotation system over the 14 years ranged from 0·58 to 0·64. However, the mean RE of P fertilizer was 0·26 (varying from 0·22 to 0·29) in the wheat–rice cropping system over the 14-year period. For every 100 kg surplus P/ha per year, the concentration of soil P extracted by 0·5 m NaHCO3 at pH 8·5 (Olsen-P) would increase by, on average, 4·12 mg/kg in soil. For the wheat–rice cropping system, the current P application rate of 55–65 kg P/ha per year is able to sustain annual yields of about 3 t/ha for wheat and 7 t/ha for rice. This study suggests that, in order to achieve higher crop yields, the P fertilizer utilization efficiency should be considered when making P fertilizer recommendations in wheat–rice cropping systems.

Six field experiments were carried out in eastern England between 2003 and 2005 to test the effect of sulphur (S) fertilizer on the yield of sugar beet (Beta vulgaris L.). The experiments were undertaken at sites where there had previously been a positive response to S in other crops or where no S-containing materials had been applied for more than 20 years. No individual experiment produced a significant positive response to S application, but the treatments that received no S fertilizer produced the smallest yield in five of the six experiments. Analysis across years using restricted maximum likelihood (REML) procedures showed that there was a positive and significant sugar yield response in beet of 0·56 t/ha where positive responses had previously been recorded in other crops grown on these loamy sand soils. Beet crops grown in soils of this type should receive S fertilizer that can be applied conveniently as sufficient ammonium sulphate to supply the first dressing of N.

Genes for adaptation to climatic conditions can have an impact on the expression of genes for agricultural productivity. This study tested the hypothesis that winter wheat cultivars registered in middle Europe (especially the Czech and Slovak Republics) during the period 1976–2009 were differentially adapted to different regions, reflecting selection for different allelic combinations. This was tested by analysing for the presence of alleles at the Rht and Ppd loci using molecular markers and gibberellic acids (GA) response tests. Four allelic variants (174, 192, 165 and 198-bp) were detected at the Xgwm261 locus linked to Rht8 on chromosome 2D. The 198-bp allele was rare, but present in some of the most widely grown cultivars. Of 85 cultivars grown in the area of Czech Republic, the 174-bp allele predominated in frequency and area (39 cultivars), often in combination with Ppd-D1b (30 out of 39 cultivars) and Rht-D1b (15 out of 30 cultivars). In neighbouring Slovakia, the 192-bp allele, generally associated with Ppd-D1a, was detected in 30 out of 40 cultivars; in 12 cultivars accompanied by a GA-insensitive allele on 4B chromosome (pedigree analyses indicated a high prevalence of the Rht-B1d allele). The 192-bp (Rht8)/Ppd-D1a linkage block was broken up in 7 out of 22 cultivars that carried the 192-bp allele in the ‘Czech collection’. Analysis of the effects of year of registration on allele frequency showed a decline in GA-insensitive cultivars released recently in both countries, and great changes in the frequency of the 2D alleles during the period 1981–2009 in the Czech Republic. The pedigrees of successful cultivars were examined to find probable sources of Xgwm261 192-bp, 174-bp and 165-bp alleles on 2D and Rht genes located on chromosomes 4B and 4D. These results will impact on breeding strategies and the exploitation of existing registered wheat cultivars in different regions and growing systems.

Jojoba [Simmondsia chinensis (Link) Schneider] is a dioecious plant grown for its seeds, which are the source of liquid wax or jojoba oil. The sex of jojoba plants cannot be determined with morphological characters until the plants reach reproductive maturity at 3 or more years old. This difficulty of early sex determination imposes severe constraints in breeding studies and in the sex allocation of seedlings in seed orchard establishment, and importantly in a priori mating designs to produce superior jojoba individuals. This study reports three new cleavage-amplified polymorphic sequence (CAPS) assays, which identify male and female individuals distinctly. One of the assays could also identify hermaphrodite jojoba plants existing in nature or obtained using mutagenesis studies.

Land-use intensification requires more farm inputs to sustain or increase farm product outputs. However, a common concern for land-use intensification is the potential deterioration of soil. The North Otago Rolling Downlands (NORD) region of New Zealand is drought prone, and although traditionally limited to extensive sheep farming, there are large-scale conversions to intensive cattle grazing operations such as dairy farming resulting from an irrigation scheme commissioned in 2006. Pallic soils (Aeric Fragiaqualf in US Soil Taxonomy) such as those in the NORD region are prone to soil compaction because of their ‘high’ structural vulnerability under intensive management. To address these concerns, a field trial was established on a common NORD Pallic soil (Timaru silt loam) to determine how land-use intensification affects indicators of soil quality (macroporosity, bulk density, structural condition score, total and mineralizable carbon and nitrogen and earthworms) and pasture production. The treatments compare irrigated v. dryland pasture and sheep v. cattle grazing on 16 plots. The findings show that soil physical quality responds more quickly to changes in land-use pressure than do biochemical and organic indicators. Both irrigation and cattle grazing, particularly in combination, increased soil compaction; macroporosity on irrigated plots grazed by cattle ranged from 9·1 to 13·3% v/v at a depth of 0–50 mm, compared to dryland plots with sheep grazing (18·9–23·0% v/v). Soil compaction/damage has implications for pasture production, soil hydrology and nutrient movement. Land management practices for intensive cattle grazing of irrigated soil prone to treading damage therefore need to implement high compaction risk strategies to avoid or ameliorate potential changes to soil quality.

In the current Dutch protein evaluation system (the DVE/OEB1991 system), two characteristics are calculated for each feed: true protein digested in the intestine (DVE) and the rumen degradable protein balance (OEB). Of these, DVE represents the protein value of a feed, while OEB is the difference between the potential microbial protein synthesis (MPS) on the basis of available rumen degradable protein and that on the basis of available rumen degradable energy. DVE can be separated into three components: (i) feed crude protein undegraded in the rumen but digested in the small intestine, (ii) microbial true protein synthesized in the rumen and digested in the small intestine, and (iii) endogenous protein lost in the digestive processes.

Based on new research findings, the DVE/OEB1991 system has recently been updated to the DVE/OEB2010 system. More detail and differentiation is included concerning the representation of chemical components in feed, the rumen degradation characteristics of these components, the efficiency of MPS and the fractional passage rates. For each chemical component, the soluble, washout, potentially degradable and truly non-degradable fractions are defined with separate fractional degradation rates. Similarly, fractional passage rates for each of these fractions were identified and partly expressed as a function of fractional degradation rate. Efficiency of MPS is related to the various fractions of the chemical components and their associated fractional passage rates. Only minor changes were made with respect to the amount of DVE required for maintenance and production purposes of the animal. Differences from other current protein evaluation systems, viz. the Cornell Net Carbohydrate and Protein system and the Feed into Milk system, are discussed.

The concepts of control charts, an important tool in statistical process control, are commonly used for monitoring industrial production processes. In the context of precision livestock farming, their use has been demonstrated by many, although the statistical properties of livestock process data often do not comply with the basic assumptions of such control charts. The focus of the current review is on the most important aspects, recommendations, pitfalls and opportunities for the development and performance of control charts on livestock process data. An important hurdle to tackle is the statistical characteristics of the raw livestock process data which are mostly violating the control charts’ assumptions. An integrated approach, like synergistic control, appears to be promising in handling this issue. The availability of real-time on-farm validation of proposed systems will be crucial for lifting them from the potential level to direct practical relevance.

The suitability of diminishing return functions such as the monomolecular and rectangular hyperbola equations, specifically re-parameterized for analysing energy balance data, has been investigated in ruminants, pigs, broilers and turkeys. In the current study, these equations were applied to a total of six time course profiles with male and female broiler breeder pullets (Ross 308 between 1 and 21 weeks of age, n=63 for each sex) in order to provide estimates for energy and protein requirements for maintenance and growth. Non-linear regression was used to estimate parameters and combine them to determine other biological indicators. All statistical computations were implemented in SAS (SAS 2000) by means of the NLMIXED procedure. The best-performing model was identified based on model behaviour when fitting the data, biologically meaningful parameter estimates and statistical performance. In spite of similarity between the biological indicators calculated for each sex using parameter estimates of the two models, quantitative examination of their predictive ability by error measurement indices showed the monomolecular model was superior. The metabolizable energy (ME) and crude protein (CP) requirements for maintenance ranged from 365 to 432 kJ/kg live weight (LW)/d and from 4·3 to 4·9 g/kg LW/d, respectively. The average ME and CP utilization ranged from 11·30 to 12·10 kJ/g body weight (BW) gain and from 0·61 to 0·64 g/g CP intake, respectively. The results obtained using the models were within the range reported by different researchers. Utilization of ME and CP for gain was more efficient at low levels of energy and protein intake, and gradually decreased as the level of energy and protein intakes increased. In conclusion, the models described herein were considered advantageous because they could predict the magnitude and direction of the responses of growing broiler breeder pullets to dietary ME and CP intake, which can be used in choosing and developing special feeding programs to decrease production costs.