Dear Friends,
I have noticed that the recently published most manuscript showed nitrogen and irrigation managements are the best adaptation strategy to cope with climate change. Unfortunately, they create environmental problem rather than increasing crop yield.
Identification of the appropriate management strategy and technologies to attain the aforesaid objective is critical. To head towards zero waste with agriculture while maintaining environmental sustainability in the future is even more daunting. Substantially, the environmental management systems can be balanced by eco-friendly practices in agriculture (manage the sowing dates), extended production responsibilities (planning for sowing management effects), and improved crop handling (reduction in water wastage). Thus, a balanced economy can be achieved by holistic and systematic thinking (crop modelling), toxic substances reduction/elimination (application of fewer fertilizers) leading to waste reduction. Apart from this, farmer awareness with the policies and ongoing research can also help in strategic management with agriculture, and thereby environment can easily be collaborated and outreached. (Srivastava et al., 2022)"
N Fertilizer
High application of N fertilizers can create environment problem as when runoff occurs those fertilizers will become pollutant. Also, ammonia emissions will be higher due to dry surface because of extreme weather. Ammonia considered as green house gas which increase the climate change. Hence, in any condition, Fertilizer can not be good adaptation strategy.
Irrigation
Further, irrigation will increase due to extreme temperature or warming climate. But, ground water is declining due to high demand for drinking and agriculture is the only sector which consume a lot of water. Hence, irrigation is also not the good adaptation strategy to cope with climate change.
Sowing dates
Other adaptation such as evolution of new variety is expensive. Hence, shifting sowing date can be a good adaptation strategy. But shifting sowing date is a local based management in India. As India is a diverse country and management can vary at regional level too. Hence local management based adaption strategy can be useful. Moreover, the estimation of crop productivity was more significant on a local scale rather than on a regional one. Implementing local approaches to improve the adaptation strategies through crop-climate modelling for the farmers and stakeholders. Hence, effective adaptation strategies need to be evaluated on a local basis first than on a regional basis to reduce the impact of climate change. Thus, modelling of adaptation strategies will be locally relevant for a longer term to be resilient to future climate change.
Sowing date as adaptation Strategy
Recent study evaluated shifting sowing dates as adaptation strategy for maize crop in Eastern India. For that Four RCP's (2.6, 4.5, 6.0 and 8.5) were used for the year period 2021-50 and 2051-2081 of 17 GCMs. Methodology is presented below.
Below figure (a and b) shows the evaluation of sowing dates to simulated average grain yield for all the sites with current climate (baseline) under rainfed and irrigated seasons using violin plot for all scenarios. Moreover, the coefficients of variables were estimated to analyze the performance of the sowing dates under rainfed and irrigated seasons.
Figure also shows that early sowing dates 25 Dec and 5 Jan are suitable for all the RCP scenarios of CMIP5 climate projections and gave higher yield under both time periods. Whilst, the late sowing dates (25 Jan and 5 Feb) were unsuitable due to high uncertainty, low grain yield than the baseline, and earlier sowing dates for both the time periods. The sowing date (15 Jan) gave a notable estimated yield but the yield deviation was high for both time slice 2050s and 2080s in all the RCP scenarios.
How shifting sowig dates affects
Thus, the early sowing dates faced a dry spell while the late sowing dates faced high rainfall, thereby indicating crop failure in both cases. The shifting sowing dates can alter the grain filling period which is beneficial for the accumulation of dry matter in the grain. In addition, the distribution of rainfall within the crop growing period can alter the effects of the temperature. Moreover, increasing CO2 can harm crop yield if the maximum photosynthesis rate is exceeded.
Above figure indicates that the earlier sowing date 30 May and late sowing date 30 June under rainfed condition, while earlier sowing dates 25 December under irrigated condition showed less reduction in grain yield in both historic and future periods. Moreover, shifting sowing dates had a larger influence in the future periods than the historic period for the Purlia and Birbhum districts, while West Medinipur and Bankura districts, earlier sowing dates showed less reduction in grain yield in comparison to the delayed sowing dates under irrigated condition. Furthermore, late sowing date 30 June had a larger influence in future periods than the historic one, while in West Medinipur district, earlier sowing dates are more influential under rainfed conditions. Thus, under the rainfed condition, the earlier sowing dates (30 May and 30 June) show a reduction effect in the grain yield in future periods in all the RCPs for all districts except the West Medinipur.
However, delaying the sowing period until 10 July had a negative effect for the West Medinipur and Bankura districts specifically. Under irrigated condition particularly, with the late sowing dates a consistent grain yield reduction was observed across all the districts in all scenarios and time periods. Also, all the sowing dates showed a reduction in yield with increasing RCP especially for RCP 8.5, and the time period 2080s had more impact on the grain yield than 2050s in comparison to the historic period.
Is it beneficial as a management ?
- Well, first of all, well calibrated model needed because of reliability and for that strong data required.
- The sowing date (5 Jan) was suitable for the time slice 2021–50 in all the RCP scenario, while earlier sowing date (25 Dec) was found to be suitable in the time slice period of 2051–80 with RCPs 8.5 for the irrigated season.
- The sowing dates, 10 and 20 Jun were effective in RCPs 2.6, and 4.5 for the time slice 2051–2080 under rainfed season.
- Effectiveness of late sowing dates was higher in RCPs 6.0, and 8.5 for both the time periods under rainfed season.
- The changing sowing dates can reduce the effect of temperature on sensitive crop growth stage in irrigated season, while it can help to meet the precipitation on the sensitive crop growth stages.
- Henceforth, the shifting of sowing dates can be adopted effectively and economically with less imports to reduce the detrimental climate change impact.
References:
https://www.sciencedirect.com/science/article/abs/pii/S0959652622002402?via%3Dihub
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