Nanobot Plant Sensors:
http://www.pnas.org/content/112/15/4541.short
http://www.tandfonline.com/doi/pdf/10.1080/17458080.2011.561453
The role Nanotech plays in fertilizers:
1. Drought resistant crops
2. Auto injecting fertilizers
3.Enhanced Formulas
Nanotechnology in soil improvement:
How Nanotubes can monitor environmental conditions:
Growing nanoparticles in plants
Nanotech Sensors in Plants
Chloroplasts are the food machine of the plant. Present in  the leaf this is where photosynthesis takes place.Chloroplasts can even now play out these responses when expelled from plants, yet following a couple of hours, they begin to separate since light and oxygen harm the photosynthetic proteins. Normally plants can totally repair this sort of harm, yet extricated chloroplasts can't do it all alone.With carbon Nanotubes seeming to go about as a "Prosthetic Photoabsorber," photosynthetic action — measured by the rate of electron move through the Thylakoid layers .
These sensors can work on the automatic deploying of fertilizers. Pesticides and insecticides can be injected when their concentrations are low...detected by these sensors.  These sensors work in the following ways:
Small gas particles are enough to trigger the electrical impulse change of carbon nano tubes and so these can be implemented in gas and nitrogen sensors.These can be used to effectively stabilize the nitrogen concentrations in the plants.
One of the boosters in this system are carbon nanotubes. Both single and double layered nanotubes are able to be used as sensors for carbon nanotubes can act as sensors for proteins and DNA. The single layered sensors are able to to have different orientations and thus depending on this they are able to exhibit various properties. This allows us to grow CNTs in different situations and then control them. Synchrotron X-radiation  and nuclear resonance have revealed atomic structures of complex molecules. Various nanotube-based gas sensors have been depicted in the previous couple of years. Scientists have built up a scaled down gas ionization locator in view of CNTs . The sensor could be utilized for gas chromatography. Titania nanotube hydrogen sensors have been joined in a remote sensor system to distinguish hydrogen fixations in the air. Furthermore, researchers have built up a concoction sensor for vaporous particles, for example, NO2 and NH3 that depends on nanotube atomic wires .Other than this, these sensors are able  to detect pollutants and infections allowing us to prepare in advance. Bacteria such as E.coli and Salmonella can be detected by these sensors which can lead to substantial advances in health care and disease prevention. Researchers at Fu Jen Catholic university used the following method to detect these bacteria For E.Coli in milk,an expendable Immunosensing strip containing antibodies for aberrant sandwich catalyst, connected to Immunoassay was manufactured  by connecting 13-nm GNPs onto screen-printed carbon terminals (SPCEs) . The cathode was combined with the E. coli O157:H7-particular immunizer, E. coli O157:H7 in place  cells and the second E. coli O157:H7-particular counter acting agent conjugatwith horseradish. The hydrogen peroxide and ferrocenedicarboxylic corrosive were utilized as a substrate.
These sensors open up an enigma of knowledge and progress. The future holds great promise if we go at our pace. The Golden Age of humanity is not far away.Nanotechnology is a generally youthful train contrasted with traditional building, and it is inalienably interdisciplinary. It appears that in many fields we are in reality quite recently starting to wander into these new measurements. Difficulties remain, be that as it may, in all parts of nanotechnology. We have to enhance imaging execution by empowering speediercope of bigger surfaces, in the end down to the sub-atomic scale. We likewise need to culminate nanopatterning techniques to enhance determination, overlay and throughput abilities. Future nanomanufacturing will in all probability depend on blends of best down building and base up self-get together. To wrap things up, we have to discover routes for the common combination of various length-scale gadgets (nano/miniaturized scale/full scale) with the goal that we can program a 'nano-usefulness' into a microsystem precisely where it is required. Such changes will at last prompt enhanced sensors and contribute not exclusively to upgrades in our personal satisfaction yet in addition to building vitality sparing frameworks that can be created with low-squander fabricating techniquestechniques.
Nanotech Sensors to Monitor Environmental conditions
Nanotechnology holds great promise for future developments in Geology and Environmental Management. Nano bots are capable of being used a mini sensor for food quality control and bacterial and microbial infections that assail our surroundings. These sensors can bind to the target and transmit all that is being recorded, being undetectable to the naked eye these are suitable in houses and building to trace gas leaks. Apart from this these sensors are really beneficial for food production. Being useful for monitoring soil conditions and helping with controlling Ph and fertilizer concentrations. Nano sensors can be used for efficient and smart delivery of agricultural natural resources such as water nutrients and other essential chemicals.  Taking into account the ongoing plethora of natural disasters Nanoparticals used as smart nano sensors can warn us of any climatic abnormality.  CO2 levels are constantly changing and their sinks can only be detected by multi sensors array. Something that is needed to control global warming.
Specialized sensors open an enigma of possibility:  Aptasensors can be used  for determination of pesticides and insecticides (e.g. phorate, acetamiprid). Other than this  isocarbophosmart nanosensors are good for predicting changing conditions that in soil.
Aptasensors alone are very interesting. Apart from detection of pesticides they can also detect heavy metal  e.g.( Hg2+, As3+, Cu2+)  effectively reducing metal poisoning in plants and animals. 
Carbon Nano Tubes (CNTs) are unique allotropes of carbon that consist of a round nanostrcuture. This structure gives them extraordinary strength and electrical conductivity  making them useful for detecting short circuits or any electrical disasters CNT sensors are more efficient then metal oxides and polymer sensors in making nanosensor arrays.