Climate change and associated uncertainties have serious direct and indirect consequences for crop production and food security in agriculture-based developing regions. Long-term climate data analysis can identify climate risks and anticipate new ones for planning appropriate adaptation and mitigation options. The aim of this study was to identify near-term (2030) and mid-term (2050) climate risks and/or opportunities in the state of Bihar, one of India’s most populous and poorest states, using weather data for 30 years (1980–2009) as a baseline. Rainfall, maximum and minimum temperatures, and evapotranspiration will all increase in the near- and mid-term periods relative to the baseline period, with the magnitude of the change varying with time, season and location within the state. Bihar’s major climate risks for crop production will be heat stress due to increasing minimum temperatures in the rabi (winter) season and high minimum and maximum temperatures in the spring season; and intense rainfall and longer dry spells in the kharif (monsoon) season. The increase in annual and seasonal rainfall amounts, and extended crop growing period in the kharif season generally provide opportunities; but increasing temperature across the state will have considerable negative consequences on (staple) crops by affecting crop phenology, physiology and plant-water relations. The study helps develop site-specific adaptation and mitigation options that minimize the negative effects of climate change while maximizing the opportunities.

This study examines the effects of tillage, residue management and cropping system intensification through the inclusion of green gram on the performance of the rice-wheat (RW) system in NW India. We hypothesized that zero tillage (ZT) with residue retention provides a means of sustainably intensifying the RW system through lower production costs and higher economic profitability, whilst at the same time minimizing soil and environmental trade-offs. To test this hypothesis, we evaluated six combinations of tillage, residue management and green gram integration in RW rotation in northwest Indo-Gangetic Plains (IGP) of India. Treatments included in the study were: rice and wheat under conventional tillage (CT) with and without green gram (CTR-CTW, CTR-CTW+GG), both crops under zero-tillage (ZT) with and without green gram (ZTR-ZTW-R, ZTR-ZTW-R+GG) and both crops under ZT plus residues with and without green gram (ZTR-ZTW+R, ZTR-ZTW+R+GG). Based on two consecutive years of data, the net return from the RW system was significantly higher in the ZT than CT systems. Methane emissions were only observed under flooded conditions in CT rice plots; otherwise, emissions were negligible in all other treatment combinations. N₂O emissions were dictated by N fertilizer application with no other treatment effects. Overall, ZT with residue retention resulted in the lowest global warming potential (GWP) ranging from −3301 to −823 kg CO₂-eq ha⁻¹ year⁻¹ compared to 4113 to 7917 kg CO₂-eq ha⁻¹ year⁻¹ in other treatments. Operational inputs (tillage, planting, and irrigation) and soil C sequestration had significant effects on total GWP. The water footprint of RW production system was about 29% less in CA-based system compared to CT-based systems. Our study concludes that ZTR-ZTW+R and ZTR-ZTW+R+GG in RW systems of northwestern IGP have the potential to be agronomically productive, economically viable with benefits also for the environment in terms of soil health and GHG emissions.

An anatomical investigation of the culm of pseudoviviparous alpine meadow grass (Poa alpina var. vivipara L.) revealed that transpiration flow, as delimited by Lucifer Yellow tracer dye, was maintained despite advanced senescence (as evidenced by loss of chlorophyll and chloroplasts), with leafy spikelets driving transpiration flow. Transpiration flow was not hindered by cavitation or tylosis in older culms, the low frequencies of these senescence processes being bypassed via nodal plexi. Despite this, water content of plantlets declined over time and water stress became apparent, suggesting that water supply via the determinate culm was not sufficient for the increasing transpirational demand of indeterminate plantlets. The implications of declining water content on the biomechanical properties of the culm, and concomitant limitations on the pseudoviviparous reproductive strategy, are discussed. Nomenclature of grass follows Hubbard.

In southern Bahia, Brazil, cacao (Theobroma cacao L.) is cultivated in landscapes with diverse physiographic attributes which may influence yield. This study aimed to evaluate the relationship between physiographic attributes — terrain slope, slope orientation relative to the sun, transmittance of photosynthetically active radiation, and rainfall — and cacao yield from the 4th to 7th year of cultivation across 15 farm field trials in southern Bahia. These trials were conducted in renovated clonal orchards under different light conditions, ranging from full sun to agroforestry systems with varying levels of shading. The results indicated that rainfall accumulated from March of the previous year to February of the analyzed year had a significant positive correlation with cacao yield. Terrain slope and slope orientations facing west and south were negatively associated with productivity, while east-facing slopes had a positive influence. The most productive areas exhibited an average transmittance of photosynthetically active radiation of approximately 70% to 80%, suggesting that light shading can enhance the microclimate and favor cacao yield. These findings highlight the importance of topography and shade management, indicating that physiographic attributes should be considered in site selection for cacao orchard renovation to support the development of high-yielding orchards.