Global warming will directly influence agricultural production and present new challenges for food security in semiarid regions of China. A warming experiment was conducted in Guyuan, China using infrared ray radiators to study the impact of warming on crop growth, yield and quality of a potato–broad bean–winter wheat crop rotation system. Warming significantly affected the crop photosynthesis rates of the potato–broad bean–winter wheat rotation system. In the podding stage of broad bean and the heading, blooming and booting stages of winter wheat, the photosynthesis rate was significantly decreased when the temperature increased by 0.5–2.0°C. The growing period of the potato–broad bean–winter wheat rotation system was shortened by 20–40 days per 3-year-period, and the fallow period was prolonged by 4–13 days per 3-year-period. The water use efficiency of the potato–broad bean–winter wheat rotation decreased by 8.6% when the temperature increased by 1.02.0°C. The yield of the potato–broad bean–winter wheat rotation increased by 6.1–7.7% when the temperature increased by 0.5–1.0°C. However, yield decreased 12.9–13.4% when temperature increased by 1.0–2.0°C. Potato protein significantly decreased by 9.3–17.6% and the winter wheat fat significantly decreased by 6.7% when the temperature increased by 0.5–2.0°C. The results indicate that global warming could seriously affect the crop growth, yield and water use of the potato–broad bean–winter wheat rotation in semiarid regions of China.

While climate change mainly applies to global warming and subsequent drought periods, freezing periods also are changing and may trigger genetic adaptation. However, there are few prospective, experimental demonstrations. This paper investigates how effectively genetic frost-resistant variants can respond differently to frost periods, especially in farmers’ fields where various other selection pressures occur. An experiment using Avena fatua variants was set up in the field over 8 years of winter crop rotation. The frequency of each variant identified by their leaf isozymes was estimated every year. Six years were necessary to observe a weak trend towards an increased frequency of the frost-resistant phenotype, while the other variants had apparent erratic behaviour. Selection of the frost-resistant variant was challenged by irregular low temperature selection pressure, differential dormancy, germination and seed production, and possibly herbicide sensitivity that mitigated the expression of the selection response. This experiment shows how plant polymorphism and farmers’ practices that superimpose habitat unpredictability diversify possible responses to selection pressures and delay adaptation. However, if climate change brings both higher mean temperatures and extreme values, changes of apparent plant phenology could happen for weeds species displaying the appropriate genetic variability within the time-frame of farmers’ career, thus necessitating correlative adaptation of farming practices.

Field trials conducted in multiple years across several locations play an essential role in plant breeding and variety testing. Usually, the analysis of the series of field trials is performed using a two-stage approach, where each combination of year and site is treated as environment. In variety testing based on the results from the analysis, the best varieties are recommended for cultivation. Under a Bayesian approach, the variety recommendation process can be treated as a formal decision theoretic problem. In the present study, we describe Bayesian counterparts of two stability measures and compare the varieties in terms of the posterior expected utility. Using the described methodology, we identify the most stable and highest tuber yielding varieties in the Polish potato series of field trials conducted from 2016 to 2018. It is shown that variety Arielle was the highest yielding, the third most stable variety and was the second best variety in terms of the posterior expected utility. In the present work, application of the Bayesian approach allowed us to incorporate the prior knowledge about the tested varieties and offered a possibility of treating the variety recommendation process as a formal decision process.

The objective of this study was to evaluate the fermentative characteristics and chemical composition of cochineal nopal cactus silage additives with urea or Lactobacillus buchneri (LB), as well as the association of both additives in four storage times (7, 15, 60 and 120 days) and during aerobic stability, with evaluations at 0, 48 and 96 h. Four silages were used: no additive, addition of 2% urea, addition of LB and addition of 2% urea and LB. The study was divided into two experiments: the first experiment evaluated the silages at different storage times, and the second experiment evaluated the silages during the aerobic stability test. In both experiments, the experimental design was completely randomized in a factorial scheme (4 × 4 and 4 × 3) with three replicates per treatment. After the ensiling process, lactic acid bacteria predominated in all treatments. The concentration of lactic acid increased significantly from 60 days of ensiling. The concentration of acetic acid varied significantly between the storage times only for the silages treated with urea and LB alone. The silage treated with urea maintained a constant pH value up to 120 days of storage. During the 96 h aerobic stability test, no breaking in the stability of silages was observed. The exclusive or associated use of urea and LB promotes improvement in the fermentative characteristics of cochineal nopal cactus silage, without major alterations in the chemical composition or interfering with the aerobic stability of the silages.

Ruminant grazing systems aim to optimize the proportion of grazed forage within the diet and perennial ryegrass grazing efficiency influences both the quantity and quality of herbage utilized. The objective of this study was to examine morphological and chemical plant characteristics and test for any associations with grazing efficiency. The leading perennial ryegrass varieties from the 2016 Irish Recommended List were established in a plot study and rotationally grazed by dairy cows over 3 years. Pre-grazing plant characteristics were measured and related to grazing efficiency, as measured by ‘residual grazed height’. Data were analysed using the PROC MIXED procedure to test for trait differences between varieties, and their corresponding ploidy and heading categorizations. Traits displaying significant variety variability were then tested for their correlation to grazing efficiency using the PROC GLM procedure. Tetraploid varieties exhibited superior grazing efficiency over diploids, due to their superior performance in traits correlated with grazing efficiency. Increasing organic matter digestibility and leaf proportion and decreasing neutral detergent fibre and stem height within the sward were found to increase grazing efficiency. The observed link between these plant traits and grazing efficiency indicates a possibility that they could be used to develop proxy measures to aid breeders to select for, and evaluators to measure, varietal grazing efficiency without involving animal assessments. It was concluded that this would make it logistically practical to assess large numbers of varieties in small plot trials to both breed and evaluate perennial ryegrass varieties for superior grazing efficiency.

Increasing crop diversity has been highly recommended because of its environmental and economic benefits. However, the impacts of crop diversity on soil properties are not well documented. Thus, the present study was conducted to assess the impacts of crop diversity on selected soil quality indicators. The cropping systems investigated here included wheat (Triticum aestivum L.) grown continuously for 5 years as mono-cropping (MC), and a 5-year cropping sequence [(wheat–cover crop (CC)–corn (Zea mays L.)–pea (Pisum sativum L.) and barley (Hordeum vulgare L.)–sunflower (Helianthus annuus L.)]. Each crop was present every year. This study was conducted in the northern Great Plains of North America, and soil quality data were collected for 2016 and 2017. Selected soil quality indicators that include: soil pH, organic carbon (SOC), cold water-extractable C (CWC) and N (CWN), hot water-extractable C (HWC) and N (HWN), microbial biomass carbon (MBC), bulk density (BD), water retention (SWR), wet soil aggregate stability (WAS), and urease and β-glucoside enzyme activity were measured after the completion of 5-year rotation cycle and the following year. Crop diversity did not affect soil pH, CWC, CWN, HWC, HWN and SWR. Cropping systems that contained CC increased SOC at shallow depths compared to the systems that did not have CC. Crop diversity increased WAS, MBC, and urease and β-glucoside enzyme activity compared with the MC. Comparison of electrical conductivity (EC) measured in this study to the baseline values at the research site prior to the establishment of treatments revealed that crop rotation decreased EC over time. Results indicate that crop diversity can improve soil quality, thus promoting sustainable agriculture.

The paper presents results from a study examining the relationship between large-scale modes of climate variability with the fluctuations in the yield of barley, durum wheat, olives and sunflower crops in Tuscany, Italy. In particular, the blocking circulation over the growing season, with associated hot and dry conditions, decreased yield for olive crops, barley and durum wheat. The teleconnections analysed in this study are the winter North Atlantic Oscillation (NAO) and the Summer North Atlantic Oscillation (SNAO); the West African Monsoon (WAM) and the Intertropical Front (ITF); and although NAO, SNAO, ITF and WAM are not strictly related to each other, the values of these indices are strongly related to the atmospheric circulation regimes and related weather types. Thus, they have an impact on precipitation and temperature patterns in Italy and on yields of important crops in Tuscany. Results show that the large-scale temperate and tropical variability directly influences the crop yield through three main circulation regimes. These patterns illustrate the importance of the large-scale modes, which, together with the associated weather types, have an impact directly on Tuscan crop yields; both barley and olive yields decline significantly when the ITF is further north with warmer and drier conditions in Italy.

It was aimed to simultaneously study standardized ileal digestible (SID) tryptophan (Trp) and lysine (Lys) for gilts. A digestibility assay was previously conducted to determine the SID amino acid in the basal diet (low levels of SID Trp and Lys). Sixty-four gilts (15.04 ± 1.44 kg) were allotted to 16 diets in a 4 × 4 factorial arrangement (1.55, 1.85, 2.15 and 2.45 g/kg SID Trp and 9.72, 11.12, 12.52 and 13.92 g/kg SID Lys) with four replicates per treatment. Performance, longissimus muscle (LM), backfat thickness (BF) and blood variables were evaluated. An interaction was observed for G:F, and by response surface model, the optimum Trp level was achieved at 2.15 g/kg (0.159 g/MJ of ME). A quadratic effect of Trp was observed on body weight (BW) and average daily gain (ADG); the daily feed intake increased linearly as Trp increased. The optimum Trp levels of 2.25 and 2.24 g/kg were estimated for BW and ADG, respectively. The BF increased with increasing levels of Trp. There was a quadratic and linear effect of Trp and Lys, respectively, on the LM, in which the optimum Trp level was determined as 2.05 g/kg in the diet. Plasma urea nitrogen decreased as Trp and Lys levels increased. Using estimates provided by response surface, maximized G:F ratio was obtained at 2.15 g SID Trp/kg of diet and at least 13.92 g SID Lys/kg of diet is necessary to optimize the G:F for 15–30 kg gilts, providing a Trp:Lys ratio of 15.4:100.