Precision Agriculture and Water Management — A case study from India

In the previous article, we published about the implementation of our Kisan App — GramworkX Crop Management. We discussed in deep, on how water management works and how interventions can be made via technologies that provide data-based decision support to farmers.

The GramworkX solution helps in quantifying and providing analytical insights towards water utilization and consumption patterns across fields, soil types and providing data support systems to farmers. The GramworkX IOT device continuously monitors key parameters in the field such as Temperature, Pressure, Humidity and Rainfall. This information is provided to the farmers real-time via the GramworkX — Kisan App. In addition, our unique Machine Learning models help with irrigation prediction and also other decision support based on micro-climatic weather conditions. After a year of research, preparing data modelling for Indian conditions, and 3+ months of on field trials and surveys, we launched the GramworkX — Kisan App (via google playstore) on 15th August 2020. While this is part one of our overall solution, this app is completely free and helps farmers quantify the water requirement for their crop. The insights are based on weather and satellite data specific to the geographical location one has provided. The free version app has the microclimatic data provided by 3rd party weather forecasting services and approximates to a larger area.

In this article we take a look at the data we have been gathering from different farmer locations that helps fortify the need for precision agriculture and how truly data can help farmers in decision making and creating a sustainable future.

Within 1 month of the App launch, we had had over 500+ farmers signing-up and over 30% creating zones (plots of land where a particular crop has been grown defined by the farmer) with crop information such as crop type, soil type and acreage of land provided by the farmer.

We have had farmers across the country setting up zones, with South and West India being our major area of reach. Below is an overview of the spread of farmers having created zones in the app, and locations of the various zones.

Figure1: Distribution of farmer using GramworkX — Kisan app across India, and have set-up their crop information
Figure 2:Split of zones by irrigation type

A majority of the users, a good 48% use drip irrigation while over 33% use flood irrigation in their farms. It was also noted that there was a good split of soil types spread across the zones created.

Figure 3: Split of zones by soil type

Over 20 crops are supported in the app, and the greatest number of zones were created for Tomatoes closely followed by Chill, Cotton and Groundnut.

While almost 20% of the zones were Tomato, by land area under cultivation Cotton, Wheat and Groundnut were the major crops covering over 30% of cultivation area amongst the zones registered.

Figure 4: Split of zones by Crop being grown
Figure 5: Crop types by area of cultivation

While that was an overview of the farmer inputs on the crops they are growing, the regions and the area. We now take you through a case study, where we have tried to understand the weather and water requirements of 2 crops — Cotton and Tomato, both sensitive to water requirements grown in two different regions of India, under same area of land and the same period of growth. We have tried to study the different parameters and gauge the benefits of precision agriculture.

I. A Case Study — irrigation requirements across 2 regions for the same crop (Cotton)

Cotton (Gossypium hirsutum) is grown for fibre and seed. The origin of cotton is still uncertain. The development of the crop is sensitive to temperature. Cool nights and low daytime temperatures result in vegetative growth with few fruiting branches. The length of the total growing period is about 150 to 180 days. Depending on temperature and variety, 50 to 85 days are required from planting to first bud formation, 25 to 30 days for flower formation and 50 to 60 days from flower opening to mature boll. No clear distinction can be made in crop growth periods since vegetative growth is continued during flowering and boll formation and flowering is continued during boll formation.

Cotton is grown on a wide range of soils but medium and heavy textured, deep soils with good water holding characteristics are preferred. Acid or dense subsoils limit root penetration. The pH range is 5.5 to 8 with 7 to 8 regarded as optimum.

Depending on climate and length of the total growing period, cotton needs some 700 to 1300 mm to meet its water requirements

In the early vegetative period, crop water requirements are low, or some 10 percent of total. They are high during the flowering period when leaf area is at its maximum, or some 50 to 60 percent of total. Later in the growing period the requirements decline. [1]

We studied the cotton crop grown across two fields in AP and MH, to understand the irrigation requirement patterns and any difference caused by weather parameters.

Figure 6: Max Temperature values across the growing period of cotton crop
Figure 7: Min Temperature values across the growing period of cotton crop
Figure 8: Average wind speed values across the growing period of cotton crop
Figure 9: Water recommendations for Cotton crop during the initial development stages
Figure 10: Water recommendations for Cotton crop during the mid season stages

Analysis Summary:

1) The above two graphs are a clear indicator that the daily water requirements of cotton crop increase in mid season stage compared to its early development vegetative state and continues to increase over time. This is expected, as the crop growth increases, the water requirements also increases.

2) While multiple factors such as Humidity, Wind and Pressure play a key role in the hydroligical cycle, a simple observation could be seen that in the initial stages the relative temperatures in MH, being lower corresponded to lesser water requirements as compared to AP. But with increasing temperatures in the later periods, the water requirements for MH increased

3) The water requirements in cotton varied by 28K litres in the total period in 2 regions

II. A Case Study — irrigation requirements across 2 regions for the same crop (Tomato)

Tomato is one of the most important vegetable crops in India. Tomato is a daylength neutral plant with a growing period of 90 to 150 days. For optimum growth, mean daily temperature of 18 to 25ºC and night temperatures between 10 and 20ºC is required. On the contrary, temperatures above 25ºC, when accompanied by high humidity and strong wind, can result in reduced yield. This is because, high humidity leads to high occurrence of pests, diseases and fruit rotting. Thus, dry climates are therefore preferred for tomato production.

Tomato can be grown on a wide range of soils but a well-drained, light loam soil is preferred. The ideal pH range can be from 5 to 7. The crop is moderately sensitive to soil salinity. The most sensitive period to salinity is during germination and therefore necessary leaching of salts is frequently practised during pre-irrigation or by over-watering during the initial irrigation application.

Tomato also has a fairly deep root system and the roots can penetrate up to some 1.5 m. The seed is generally sown in nursery plots and within 10 days the seeds tend to emerge. Seedlings are then transplanted in the field after 25 to 35 days. The maximum rooting depth is reached about 60 days after transplanting.

Total water requirements after transplanting, of a tomato crop grown in the field for 90 to 120 days, can somewhere be around 400 to 600 mm, depending on the climate.

Regions of crop cultivation

A study, similar like cotton was conducted for tomato, where in two farmers in AP and MH had grown tomato crops under nearly similar acreage and same irrigation type (drip irrigation). The results showed some interesting trends and falsified common misconceptions that people tend to have with climatic parameters.

Figure 11: Max Temperature values across the growing period of Tomato crop
Figure 12: Min Temperature values across the growing period of tomato crop
Figure 13: Windspeed values across the growing period of tomato crop
Figure 14: Water recommendations for Tomato crop during the initial development stages
Figure 15: Water recommendations for Tomato crop during the initial development stages

Analysis Summary:

1) It is evident from the above plots that the daily water requirements are relatively higher for tomato crops during their mid-season stage than early development stage. This is expected, as the crop growth increases, the water requirements also increases.

2) It is a common misbelief that higher the temperature in farm, more the amount of water needed for irrigation. As shown above even though the minimum and maximum temperatures are higher in AP than MH during the development stage, the water requirements in MH are more throughout the period. This is because windspeed is also a crucial factor that farmers tend to overlook. The average windspeed is higher in MH than AP, in which case the airborne water particles are swept away faster, making more room for evaporation, thus leading to higher water requirements.

Such kind of data driven agri-tech practices help irrigate the crop and not the land. With the growing population and diminishing resources, there is an urgent need to take action to make agriculture more efficient and enable data driven resource management.

In India the input subsidies and commodity price policies favour crops like paddy that are water intensive. Several states offer free electricity to draw out groundwater for irrigation. In Punjab (North India) over-exploitation of ground water due to subsidies on power has already led to an alarming situation. We have talked in depth about Water usage policies and technology intervention requirements in agriculture in India previously.

Our aim at GramworkX is to provide more crop with less drop and to as many farmers as possible. Hence the daily water loss services is provided to our farmers via the Kisan app for free across India, in 5 languages. While this technology primarily uses satellite and weather station data to provide recommendations and predictions, our upcoming implementations with the IOT device aims to bring a higher resolution and precision in farming.

We strongly believe in incorporating analytics, automation, product and process innovation for better resource utilisation and help increase the productivity in the field of agriculture.

Want to know more about us and our technology? — Connect with us at hello@gramworkx.com or check out https://gramworkx.com/

References:

[1] FAO Crop Information: Cotton

[2] FAO Crop Information: Tomato

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