The Combined Effect of Biochar and Mineral Fertilizer on Triticale Yield, Soil Properties under Different Tillage Systems

This study examined the effect of study time, biochar dose, and fertilization-tillage system on the improvement of sandy loam physical-chemical properties and triticale grain yield. The soil properties (water holding capacity (WHC), wettability, moisture content (MC), organic matter content (SOM), pH, and electrical conductivity (EC) were monitored in short time intervals (after 3, 6, 12, and 24 months). Soil was tilled in two methods (shallow ploughless tillage and direct drilling), fertilized with nitrogen, phosphorus, and potassium (NPK) fertilizers, and amended with three hydrophobic pine wood biochar doses (0 t/ha; 5 t/ha; 15 t/ha). It was found that 15 t/ha biochar dose had the highest effect on the soil’s physical-chemical properties improvement (SOM increased by 33.7%, pH—by 6.84%, EC—by 23.4%, WHC—by 8.48%, and MC—by 21.8%) compared to the variants without biochar. Direct drilling, fertilization with NPK fertilizers and 15 t/ha biochar dose significantly influenced the rise of soil’s physical-chemical properties and triticale yield (3.51 t/ha).

Spatial and Temporal Stability of Weed Patches in Cereal Fields under Direct Drilling and Harrow Tillage

The adoption of conservation agriculture (CA) techniques by farmers is changing the dynamics of weed communities in cereal fields and so potentially their spatial distribution. These changes can challenge the use of site-specific weed control, which is based on the accurate location of weed patches for spraying. We studied the effect of two types of CA (direct drilling and harrow-tilled to 20 cm) on weed patches in a three-year survey in four direct-drilled and three harrow-tilled commercial fields in Catalonia (North-eastern Spain). The area of the ground covered by weeds (hereafter called “weed cover”) was estimated at 96 to 122 points measured in each year in each field, in 50 cm × 50 cm quadrats placed in a 10 m × 10 m grid in spring. Bromus diandrus, Lolium rigidum, and Papaver rhoeas were the main weed species. The weed cover and degree of aggregation for all species varied both between and within fields, regardless of the kind of tillage. Under both forms of soil management all three were aggregated in elongated patterns in the direction of traffic. Bromus was generally more aggregated than Lolium, and both were more aggregated than Papaver. Patches were stable over time for only two harrow-tilled fields with Lolium and one direct-drilled field with Bromus, but not in the other fields. Spatial stability of the weeds was more pronounced in the direction of traffic. Herbicide applications, crop rotation, and traffic seem to affect weed populations strongly within fields, regardless of the soil management. We conclude that site-specific herbicides can be applied to control these species because they are aggregated, although the patches would have to be identified afresh in each season.

Establishing plantain in spring in existing perennial ryegrass pastures in northern Tasmania

Research has shown advantages of including plantain (Plantago lanceolata L.) in grazed perennial ryegrass (Lolium perenne L.)-based dairy pastures. Plantain is typically established in dairy pastures during paddock renovation, and included in a mixture with perennial ryegrass. While perennial ryegrass can persist for years, even decades, plantain plant numbers and productivity decline within a few years of establishment. Maintaining the advantage of plantain requires frequent re-establishment. The current research tested the efficacy of two sowing methods (direct-drilling and broadcasting) and three sowing rates (2.5, 5.0, and 7.5 kg of seed/ha) for establishing plantain in existing irrigated perennial ryegrass pastures. Research was conducted on five dairy farms in northern Tasmania, Australia. Sowing occurred in mid-spring 2017, immediately after paddocks were grazed. Plantain establishment was monitored until early autumn 2018. Paddocks were managed as per normal farm practice, resulting in plantain being first grazed ~4 weeks post-sowing, before plants had developed to the recommended minimum six-leaf stage. Dry weather, timing of first grazing after sowing and insect burden challenged plantain establishment. However, both direct drilling and broadcasting were shown to successfully establish plantain into existing perennial ryegrass pastures.

Establishment of plantain into existing pastures

In recent years plantain (Plantago lanceolata) has emerged as a potential forage for reducing nitrogen losses from dairy farm systems. However, achieving sufficient proportions of plantain in pastures to help meet target reductions in nitrate leaching presents on-farm challenges. To investigate sowing methods for establishing plantain into existing pasture to achieve high plantain populations, direct drilling was compared with broadcasting before and after grazing. Additionally, pre-graze mowing versus grazing only, and early versus late first defoliation after sowing were investigated to assess their effect on reducing competition from existing pasture. Botanical composition was determined in a small-plot study at Lincoln following summer sowing under irrigation, and from commercial dairy farms in Canterbury (irrigated) and Waikato (not irrigated). Generally, direct drilling was more effective than broadcast sowing for establishing plantain. The method of defoliation after sowing (pre-graze mowing or grazing) was not as important as timing of early defoliation in the resulting plantain populations. Early grazing, while seedlings were small enough to avoid defoliation, improved plantain establishment likely by reducing competition from the pre-existing pasture.

A paddock survey of on-farm plantain use

The use of narrow-leaved plantain (Plantago lanceolata) in pasture sowing mixtures has recently increased following research demonstrating the value of the ‘Tonic’ cultivar in reducing cattle urinary N concentration, with likely benefits for reducing N leaching from pasture systems. The purpose of this study was to document the ways in which farmers are using plantain, investigate the factors that enhance successful establishment and persistence, and to test a method of visual estimation of plantain content in paddocks. This information will support verification of animal intake, given that there is evidence that a critical level of plantain is required in the diet to achieve significant effects on N cycling. In grass-based pastures, plantain content declined with age since sowing and few paddocks had more than 20% of their available dry matter as plantain after three years. A systematic visual assessment of plantain cover correlated well with a formal visual dry matter assessment and could be used to establish when plantain content at a paddock scale is >20–30%. Plantain content tended to be highest when sown without grass, when established by direct drilling and on clay soils, but optimal sowing rates have yet to be determined.

Management of Herbicide-Resistant Corn Poppy (Papaver rhoeas) under Different Tillage Systems Does Not Change the Frequency of Resistant Plants

Corn poppy (Papaver rhoeasL.) is the most widespread broadleaf weed species infesting winter cereals in Europe. Biotypes that are resistant to both 2,4-D and tribenuron-methyl, an acetolactate synthase (ALS) inhibitor, have evolved in recent decades, thus narrowing the options for effective chemical control. Though the effectiveness of several integrated weed management (IWM) strategies have been confirmed, none of these strategies have been tested to manage multiple herbicide–resistantP. rhoeasunder no-till planting. With the expansion of no-till systems, it is important to prove the effectiveness of such strategies. In this study, a field experiment over three consecutive seasons was conducted to evaluate and compare the effects of different weed management strategies, under either direct drilling (i.e., no-till) or intensive tillage, on a multiple herbicide–resistantP. rhoeaspopulation. Moreover, evaluations were carried out as to whether the proportions of ALS inhibitor–resistant individuals were affected by the tillage systems for each IWM strategy at the end of the 3-yr period. The IWM strategies tested in this research included crop rotation, delayed sowing, and different herbicide programs such as PRE plus POST or POST. All IWM strategies greatly reduced the initial density ofP. rhoeaseach season (≥ 95%) under either direct drilling or intensive tillage. After 3 yr, the IWM strategies were very effective in both tillage systems, though the effects were stronger under direct drilling (~95%) compared with intensive tillage (~86%). At the end of the study, the proportion of ALS inhibitor–resistant plants was not different between the IWM strategies in both tillage systems (94% on average). Therefore, crop rotation (with sunflower [Helianthus annuusL.]), delayed sowing, or a variation in the herbicide application timing are effective under direct drilling to manage herbicide-resistantP. rhoeas. Adoption of IWM strategies is necessary to mitigate the evolution of resistance in both conventional and no-till systems.

Effect of Tillage Systems on the Dissipation of Prosulfocarb Herbicide

Crop management practices such as tillage can influence the dissipation of herbicides in soil. This study aimed to determine the effects of tillage systems on soil dissipation of prosulfocarb (PSC) using two assessment methods: bioassay and high-performance liquid chromatography (HPLC) analysis. PSC was applied on plots cultivated under three tillage systems (moldboard plowing, tine tillage at 8- to 10-cm soil depth, and direct drilling) at different rates (0, 500, 1,000, 2,000, 4,000 and 8,000 g ai ha−1) and two spraying times, representing early and late sowing time of winter cereals in Denmark. The experiment was conducted over 2 yr. The soil was analyzed for PSC residues by HPLC and a bioassay, using silky windgrass as the indicator plant. Neither technique revealed an effect of tillage systems on PSC dissipation, but the LD50values estimated based on the bioassays were generally lower under direct drilling (11.7 d) than with plowing (17.5 d). Moreover, LD50estimates based on bioassay results were generally lower than those estimated with HPLC analyses. Half-life values estimated with HPLC were low and not within the range of values reported in the literature (ca. 20 d), suggesting enhanced degradation of PSC. In addition to influencing the performance of PSC against problematic weed species, an enhanced dissipation rate could also hamper the benefits of PSC in an antiresistance strategy.

Energy Consumption and Production Pattern in Direct Drilling Wheat in Punjab

The study was conducted on input energy consumption for wheat production in irrigated condition at Punjab Agricultural University, Ludhiana. The results revealed that the highest input energy requirement of 15682.9 MJha-1was recorded for conventional tillage (CT) compared 13189.4, 12467.6 and 12467.6 MJha-1 for rotavator (RT), happy seeder (HS) and zero tillage (ZT), respectively. Nitrogen (N) application showed a positive relationship with input energy consumption and highest of 18297.0 MJha-1 was recorded with 150 kg Nha-1 compared 15164.5, 13651.3, 6694.7 MJha-1 for 0, 100 and 125 kg Nha-1, respectively. The main source of input energy use was fertilizer and irrigation. The higher share of direct and non-renewable input energy consumption was recorded in CT and indirect and renewable input energy consumption was higher in HS, ZT and RT. Direct & renewable and indirect & non-renewable input energy showed a negative and positive relationship with N rates. CT wheat with 150 kg Nha-1 produced the highest total output energy. The results showed that the highest 10.48, 0.38 kgMJ-1 and 3.96 MJkg-1 of output: input ratio, energy productivity and energy specific under ZT, ZT and CT, respectively. However, the maximum NPK energy equivalent in biomass was recorded in CT. Input: output ratio, energy productivity and NPK energy equivalent showed negative relationship and energy specific showed a positive relation with N rates. CT showed the higher net gain of energy compared to direct drilling methods as ZT, HS and RT.