**1.8 Climate change in India and Assam**

Climate change and its variability are emerging as major challenges facing Indian agriculture. The high inter and intra-seasonal variability in rainfall distribution, rainfall events, and extreme temperature are causing crop damages and losses to the farmers [12]. In many parts of India, the frequency of occurrence of cold nights declined, while the frequency of occurrence of warm nights and warm days significantly

#### **Figure 1.**

*Average annual rainfall, normal rainfall, and the deviation for Lakhimpur district of Assam (2010–2021).*

#### **Figure 2.** *Average seasonal rainfall for the Lakhimpur district of Assam (2010–2021).*

*Adaptation Strategies for Climate Variability in the High Rainfall Zone of India, Assam DOI: http://dx.doi.org/10.5772/intechopen.107045*

#### **Figure 3.**

*Average annual rainfall, normal rainfall, and the deviation for Biswanath district of Assam (2010–2021).*

#### **Figure 4.**

*Average seasonal rainfall for Biswanath district of Assam (2010–2021).*

increased. Overall climate change pattern has already begun affecting the Indian agriculture sector adversely by enhancing abiotic and biotic stress to the crops and livestock. Various future climate models indicate a consistent warming trend over India, in short, mid as well as long-term scenarios [13]. Overall, the temperature rise is likely to be much higher during the *rabi* (October/November to January/February) than the *Kharif* (June/July to October/November) season. In addition, droughts and floods as well as cold and heat waves are likely to increase due to increased variability in temperature and may cause crop losses up to 30% by 2080. Assam also exhibits warming trends throughout with minor spatial variations. Analysis of temperature data from 1961 to 2010 revealed a warming trend in mean maximum temperature over Dibrugarh (0.120°C) per year, Jorhat (0.006°C per year), Nagaon (0.007°C/per year, Diphu (0.001°C per year and Guwahati 0.016°C. Tezpur, however, showed a decreasing trend of mean maximum temperature at the rate of 0.007°C per year. The magnitudes of trends of minimum temperature were higher compared to maximum temperature. The long-term (1901 to 2010) mean annual rainfall of the Brahmaputra basin is 2293 mm with a standard deviation of 225 mm. Barak valley basin receives 3204 mm rainfall with a stand's deviation of 420 mm. On an annual basis, a long-term decreasing trend of rainfall has been observed in both the basins [11].


#### **Table 4.**

*Major rainfed crops of Assam [5].*

As per the findings of the State Action Plan for Climate Change, the annual mean temperature has increased by 0.59°C and the annual rainfall has decreased by −2.96/ mm per year over the last six decades (1960–2000). Climate change projections for Assam indicate that the mean average temperature is likely to rise by +1.7–2.2°C by

*Adaptation Strategies for Climate Variability in the High Rainfall Zone of India, Assam DOI: http://dx.doi.org/10.5772/intechopen.107045*


**Table 5.**

*Normal sowing window of the rainfed crops.*

mid-century between 1971 and 2000. There is likely to be an increase in extreme rainfall events by +5 to 38%, including floods. There is a chance of an increase in droughts weeks are going to rise as well, by more than 75% concerning the baseline (1971–2000) in the southern districts of Assam. As regards floods, projections increase the rise in events by more than 25% [14].

#### **1.9 Impact of climate change on agriculture of Assam**

The impact of climate change on agriculture is both direct and indirect. The direct impact of climate change would be small on rainy season crops but the crops will become vulnerable due to increased incidence of weather extremes, such as changes in rainy days, rainfall intensity, duration and frequency of drought and flood, diurnal asymmetry of temperature, change in humidity, and pest incidence and virulence. Winter crop production may become more vulnerable and the climate impact on cereals will vary widely in the rainy season as well as the winter season. Rainfed agriculture is likely to be more vulnerable because of the high dependency on monsoon and aberrant behavior of the south-west (SW) monsoon [15].

#### **1.10 Farm mechanization**

Agricultural productivity goes hand in hand with the mechanization of different agricultural operations, which aims at achieving timeliness of operations, efficient use of inputs *viz.,* seed, fertilizer, and chemicals, *etc.*, improvement in quality of produce, safety and comfort of farmers, reduction in the cost of produce and drudgery of farmers [16]. Mechanization would increase land and labor productivity and reduce the drudgery of humans and animals. In the changing climatic environment, the frequency of destructive weather aberrations (such as heat waves, heavy rainfall events, drought, and floods) affects the agriculture sector more vulnerable. In such situations, timely completion of farm operations is very important, which could be accomplished through the use of improved implements and machines. Thus, mechanization is the key to building climate-resilient agriculture in the country [17, 18].

Assam has the largest cultivable plain land in northeast India but power consumption for mechanization is 0.75 kWha−1, which is still below the national average of 1.5 kWha−1. For sustainable food grain production and drudgery reduction, the mechanization of agriculture is mandatory to an optimum level. Three main sources of farm power being utilized for these tools, machines, and equipment are manual (human), draft animal, and mechanical power. In many developing countries, up to 80% of farm power is provided by animal sources of power (**Table 6**) [18].

#### **1.11 Real-time contingency planning–concept**

Real-time contingency planning is considered as "any contingency measure either technology related (land, soil, water, and crop) or institutional and policybased, which is implemented based on real-time weather pattern (including extreme events) in any crop growing season" [19]. Real-time contingency planning (RTCP) was conceptualized to minimize crop production and productivity losses and to improve the efficiency of the rainfed production system. The major objectives of RTCP are:

*Adaptation Strategies for Climate Variability in the High Rainfall Zone of India, Assam DOI: http://dx.doi.org/10.5772/intechopen.107045*


#### **Table 6.**

*Farm types of machinery and implements mostly used by the farmers of the region [5].*


#### **1.12 Crop and cropping system to cope with weather aberration**

The whole concept of farming revolves around the seed. Identification of crops and varieties that fit well into changed climatic conditions is a common denominator for sustainable crop production in all land use conditions. An ideal variety should be high yielding, plastic enough to withstand weather aberration, tolerant to multiple abiotic and biotic stresses, responsive to augmented carbon dioxide levels and fit well to farming situations. Sowing the right varieties of the right crops at the right time under the right land use conditions makes a significant difference in attaining higher yields. Efforts have been made by ICAR and State Agricultural Universities to develop high yielding varieties (HYVs) suitable for biotic and abiotic stresses. The shortduration varieties and several climate-ready varieties have already been released to cope with the aberrant climatic conditions.

### **1.13 Weather aberration during the last decade**

Due to aberrant weather conditions, Indian agriculture, in general, is experiencing the delayed onset of monsoon, deviation in rainfall, early season drought, mid-season drought, terminal drought, and flash floods. Most of the studies during the last decades in India have pointed out that India's annual rainfall, together with monsoon rainfall, is trendless and is mainly random in nature over a long period, particularly on an Indian scale. However, large inter-annual and decadal variations have been observed. The summer monsoon rainfall has sown significant decreasing trends in the subdivision of south Assam (−12.5 mm) per decade. The declining trend of annual rainfall at a rate of 7.9 mm/100 years is also reported [10]. The summer monsoon rainfall in the region is decreasing (−48.0 mm/100 years), while rainfall during the post-monsoon season showed an increasing tendency (36.3 mm/1000 years).

### **1.14 Crop production architecture**

Packages for climate neutral variety, flood stress resistant variety, and insect pest resistant/tolerant varieties are to be developed over the years. Science of robotic application in production farm for weed management, etc., and application of GPS in farm planning and soil fertility management will have to be perfected.

Opinions for and against the SRI method of rice cultivation will require to be scientifically assessed to bring in needed refinement for water saving method of rice production. Designing and prototyping suitable farm types of machinery to suit changed crop production planning will need focused attention. A multidisciplinary team involving an agronomist, plant breeder, biotechnologist, meteorologist, entomologist and pathologist, and engineers will have to come together to remodel the crop production module. A team consisting of an expert from different branches of horticulture will have to initiate research to develop smart farming for small farmers, a model of hi-tech/climate control horticulture spreading the dimension to the hydroponic and aeroponic horticulture, including vertical space utilization in the greenhouse and soil-less farming, rooftop farming, *etc*.

The way the rainfall pattern is changing–sometimes early, sometimes late, sometimes scanty, sometimes in excess, sometimes erratic. Therefore, our established method of crop production will demand a change, necessitating advancing sowing time in some cases and delaying the time in some others.

Since 2011, under National Innovations in Climate Resilient Agriculture (NICRA), 23 centers of AICRPDA are conducting on-station and on-farm demonstrations/trials under NICRA with a focus on RTCP implementation and preparedness to cope with weather aberrations. Similarly, alternate and resilient crops and cropping systems are demonstrated in AICRPDA-NICRA villages as preparedness to cope with weather aberration.
