Economic analysis of organic cropping systems under different tillage intensities and crop rotations

Costs of production and organic price premiums are defining factors influencing the economic viability of organic crop production systems. Different agronomic practices, such as crop rotation and tillage intensity, are known to affect the economic performance of the production systems. The aim of this study was to compare the impact of two crop rotation sequences (simplified and diversified) and two levels of tillage intensity (high and low) on the cost of production, gross return and gross margin of crops when grown under organic management in the semi-arid Brown soil zone of the Canadian Prairies. The 2-year simplified rotation sequence consisted of forage pea (Pisum sativum L.) grown as a green manure followed by hard red spring wheat (HRSW) (Triticum aestivum L.), while the 4-year diversified rotation sequence was forage pea green manure followed by flax (Linum usitatissimum L.) or yellow mustard (Sinapis alba L.), field pea or lentil (Lens culinaris L.) and HRSW. Our hypothesis that a more diversified crop rotation would increase profitability over a traditional simplified crop rotation was supported by the findings. However, the findings did not support our hypothesis that reducing tillage intensity, and the combination of tillage reduction and diversified crop rotation through a synergetic response, would further enhance profitability. Analysis of the breakeven prices and breakeven yields for crops indicated the importance of adopting diversified crop rotations and choosing crops with high organic price premiums as means to maximize the long-term profitability of organic cropping systems.

Considerations for Selecting Potassium Placement Methods in Soil

Placement strategies can be a key determinant of efficient use of applied fertilizer potassium (K), given the relative immobility of K in all except the lightest textured soils or high rainfall environments. Limitations to K accessibility by plants caused by immobility in the soil are further compounded by the general lack of K-stimulated root proliferation in localized soil zones enriched with K alone, compared with root proliferation due to concentrated N and P. Further, effects of K fixation reactions in soils with certain clay mineralogies and the declining concentration and activity of soil solution K with increasing clay content can also limit plant K acquisition. Variation in root system characteristics among crops in a rotation sequence and fluctuating soil moisture conditions in fertilized soil horizons in rain-fed systems increase the complexity of fertilizer placement decisions to ensure efficient K recovery and use. This complexity has resulted in extensive exploration of fertilizer K application strategies, with this chapter focusing on K applications to the soil. Issues discussed include comparisons of broadcast versus banded applications, depth of fertilizer placement, and the impacts of co-location of K with other nutrients. While research findings are often specific to the crop, soil, and seasonal conditions under which they are conducted, we attempt to identify strategies that most consistently deliver improved crop recovery and utilization of fertilizer K.

Agronomic and Economic Effects of Irrigation and Rotation in Peanut-based Cropping Systems

ABSTRACT Although the Southeast U.S. receives an average annual precipitation of 1300 mm, crop yields are often limited by erratic seasonal rainfall distributions. Studies were conducted from 2001 through 2017 at the USDA/ARS Multi-crop Irrigation Research Farm in Shellman, GA (84°36′ W, 30°44′ N) on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults). The objective of this long-term study is to evaluate the effects of irrigation and crop rotation sequencing consisting of peanut, corn, and cotton on yield and net economic returns to both variable and total costs. Analysis included the entire study period and was also separated for years with below and above average rainfall. When averaged across all years, irrigation increased peanut, corn, and cotton yield and net returns compared with non-irrigation. Six different rotation sequences were addressed inclusive of continuous peanut, one year out of peanut with corn or cotton, and two years out of peanut with combinations of corn and cotton. In both irrigated and non-irrigated peanuts, the least and greatest yields were from continuous peanut and the two year out rotations, respectively. No peanut yield difference resulted with corn or cotton rotation partners for the rotation sequence. Length of rotation between peanut years did influence peanut yield and net returns. Profitability and optimal rotation sequence within any cropping system depended on irrigation, yield, crop price, and production costs for peanut, corn, and cotton.

Comparative bioenergy estimation of field crop rotations using perennial and annual grasses in the Rostov region

Annual and perennial grasses are important not only as a source of green fodder, hay, silage, grass meal and haylage in feed production, but also as good forecrops, due to the ability to accumulate biological nitrogen in the soil (since it decreases the cost of mineral fertilizers), to disinfect the soil from micro zoo pests, to improve the physical condition of the soil (since it decreases soil density). Perennial grasses are also an important component of biologized crop rotations, since the amount of crop residues remaining in the soil after harvesting is several times greater than after winter crops. The field trials were conducted in 2009–2016 by the staff of the laboratory of row crop cultivation technology of the FSBSI “Agricultural Research Center “Donskoy”. The experimental plot is located in the southern soil-climatic zone of the Rostov region (with insufficient and unstable moisture). The soil of the experimental plot is ordinary heavy loamy chernozem on loesslike loams, with 3.2% humus, neutral pH, and a high content of movable phosphorus and exchange potassium according to Machigin. The current paper has presented a bioenergetic estimation of grain (4-crop rotation sequence with annual grasses included) and biologized (8-crop rotation sequence with 25% perennial grasses) crop rotations. It has been established that nutrients’ amount per 1 ha of crop rotation area of biologized crop rotation is higher than in grain crop rotation on 22% of dry matter, on 40% of raw protein and on 39% of metabolic energy. Energy consumption per 1 kg of raw protein is lower on 27%.

NGTS clusters survey – I. Rotation in the young benchmark open cluster Blanco 1

ABSTRACT We determine rotation periods for 127 stars in the ∼115-Myr-old Blanco 1 open cluster using ∼200 d of photometric monitoring with the Next Generation Transit Survey. These stars span F5–M3 spectral types (1.2 M⊙ ≳ M ≳ 0.3 M⊙) and increase the number of known rotation periods in Blanco 1 by a factor of four. We determine rotation periods using three methods: Gaussian process (GP) regression, generalized autocorrelation function (G-ACF), and Lomb–Scargle (LS) periodogram, and find that the GP and G-ACF methods are more applicable to evolving spot modulation patterns. Between mid-F and mid-K spectral types, single stars follow a well-defined rotation sequence from ∼2 to 10 d, whereas stars in photometric multiple systems typically rotate faster. This may suggest that the presence of a moderate-to-high mass ratio companion inhibits angular momentum loss mechanisms during the early pre-main sequence, and this signature has not been erased at ∼100 Myr. The majority of mid-F to mid-K stars display evolving modulation patterns, whereas most M stars show stable modulation signals. This morphological change coincides with the shift from a well-defined rotation sequence (mid-F to mid-K stars) to a broad rotation period distribution (late-K and M stars). Finally, we compare our rotation results for Blanco 1 to the similarly aged Pleiades: the single-star populations in both clusters possess consistent rotation period distributions, which suggests that the angular momentum evolution of stars follows a well-defined pathway that is, at least for mid-F to mid-K stars, strongly imprinted by ∼100 Myr.

Effect of Two Different Types of Olympic Rotation Order on Cardiovascular and Metabolic Variables in Men’s Artistic Gymnastics

The rotation sequence-order differs from a gymnast to another according to the draw at the time of the qualifying competitions in men’s artistic gymnastics. Only the six best gymnasts start on the floor exercises, the others could start on any of the other five apparatuses. It has been demonstrated that some gymnastics events are physiologically less taxing than others; hence some gymnasts could experience lower and/or higher levels of cardiovascular and metabolic stress compared to others, depending on the apparatus they start with. In this regard, the objective of this investigation was to compare cardiovascular and metabolic variables between two different types of Olympic rotation-order; one began with the floor exercises and the other began with the pommel horse. Six elite male gymnasts took part in this investigation. Heart rates, synchronized with real-time video acquisition, as well as capillary lactate concentration following each apparatus routine were monitored. Cardiovascular and metabolic stresses were significantly higher when gymnasts started their rotation with the pommel horse in all apparatuses except the pommel horse. The floor exercises’ score was significantly affected when gymnasts ended up their competition on this apparatus. As a conclusion, starting gymnastics’ competition on the floor exercises implicates less cardiovascular and metabolic stress associated with better performance compared with the other rotation order. As a matter of fact, best gymnasts who start on this apparatus could have a slight advantage compared with the other athletes.